---
product_id: 25915919
title: "USB to Serial 4 Port DB-9 RS-232 Adapter with FTDI Chip"
brand: "serialgear"
price: "800 zł"
currency: PLN
in_stock: true
reviews_count: 4
category: "Serial Gear"
url: https://www.desertcart.pl/products/25915919-usb-to-serial-4-port-db-9-rs-232-adapter
store_origin: PL
region: Poland
---

# Up to 921.6Kbps baud rate 4 DB-9 serial ports 512-byte FIFO buffer per port USB to Serial 4 Port DB-9 RS-232 Adapter with FTDI Chip

**Brand:** serialgear
**Price:** 800 zł
**Availability:** ✅ In Stock

## Summary

> 🔗 Connect like a pro—4 ports, zero hassle, infinite possibilities!

## Quick Answers

- **What is this?** USB to Serial 4 Port DB-9 RS-232 Adapter with FTDI Chip by serialgear
- **How much does it cost?** 800 zł with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.pl](https://www.desertcart.pl/products/25915919-usb-to-serial-4-port-db-9-rs-232-adapter)

## Best For

- serialgear enthusiasts

## Why This Product

- Trusted serialgear brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Deep FIFO Buffers:** 512-byte FIFO per port ensures smooth, uninterrupted data flow even under heavy loads.
- • **Smart Plug & Play:** Seamless USB installation with automatic driver recognition—get up and running instantly.
- • **Quad-Port Powerhouse:** Expand your connectivity with 4 simultaneous RS-232 serial ports—perfect for multitasking pros.
- • **Universal Compatibility:** Works effortlessly with PCs, thin clients, and servers—future-proof your serial connections.
- • **Blazing Fast Data Transfer:** Experience ultra-reliable communication speeds up to 921.6Kbps—no lag, no limits.

## Overview

The USBG-BAY4 is a professional-grade 4-port DB-9 RS-232 to USB serial adapter featuring an FTDI chip for reliable, high-speed data transfer up to 921.6Kbps. It supports plug-and-play installation with automatic driver setup and includes 512-byte FIFO buffers per port to ensure smooth communication, making it ideal for expanding COM ports on PCs, thin clients, and servers.

## Description

Product description Features The USBG-BAY4 is a 4 port DB-9 RS232 Adapter to USB that is designed for PC, thin client, or server to provide 4 instant DB-9 RS-232 COM port expansions from the Universal Serial Bus (USB) host. This 4 port DB-9 RS232 Adapter provides the flexibility to quickly adapt to new USB technologies. Multiple modules can be added to a single USB interface allowing you to add 1 to 4 serial RS232 port connections as needed helping your network grow with your requirements. With the USB Plug-and-Play features, you can simply plug in and follow the instructions of Install Wizard, You’re ready to use your serial devices once the installation is complete. Going through a configuration with the Serial DB-9 RS-232 Adapter for Card Slots, I/O address, IRQ jumpers, DMA and others when you are connecting the devices is not necessary as the system will recognize the device and install the drivers automatically. Mechanical Form Factor: 6.83”(L) x 3.83”(W) x 0.96”(H) (17.35 x 9.72 x 2.43 cm) Weight: 1lb. Rigid Metal Case for Critical Applications Power Specifications Supports 3-wire RS232 Signals (TXD, RXD, GND) Four Port Serial RS-232 DB-9 Box USB Converter Baud Rate from 75 bps to 921.6Kbps 512-Byte Deep FIFOs for each Port Supports 7,8 Data Bits Supports 1, 1.5 and 2 Stop Bits Supports USB Bus Power DC Jack for Optional DC 5V Power Input Package Contents 4 port USB to Serial adapter USB A to B cable Paper installation manual Driver Disc About Coolgear Industrial-Grade USB Technology By pairing innovative products with excellent support, Coolgear Inc. has become a leading manufacturer of commercial-grade USB hubs, chargers, serial adapters, devices and cables. They’re easy to install but powerful enough for the most cutting-edge applications.

Review: Excellent 4 Port USB to Serial Adapter - Uses the FTDI 232RL chipset with support for the chipset's full RS232 performance, 300bps to 921.6Kbps. Compatible with Linux, MacOS 8, MacOS 9, MacOS X, Windows XP, Windows Vista and Windows 7. Also, works with 64bit versions of the OSes listed that support 64bit. It worked in Linux with 2.6 to 3.x kernels and Windows 7 without the need to install drivers. Windows XP was able to download the drivers. Drivers are provided on the included CD and newer drivers are on their site. The device is small and works well. This device is awesome, but I have two complaints. 1) The ports are close together so it is hard to use some connectors next to each other. 2) In Linux once a port was accessed, if I unplugged the device and connected it again, the ports that have been accessed can no longer be accessed. Ports that were not accessed previously can be accessed until the next unplug and replug. A restart fixes the issue. I imagine this is more related to the driver that my Linux OS was using and/or there may be a method that can allow access again without a restart that I have not found yet.
Review: Pro grade - This is not your cheap, plastic adapter. This is well built of metal and shielded with a good chip set. For that you have a fairly large piece of equipment that is larger and heavier than most other similar products. It works as advertised and is RF proof for use in radio applications. I had no problems with my Windows 7 machine. Drivers worked with no problem and 4 comm ports were created in the OS. You can use external DC power, but it will take power from the USB buss easily enough.

## Features

- USBG-BAY4 is a 4 port DB9 RS232 to USB serial adapter that is designed for PC, thin client, or server to provide instant COM port expansion via the Universal Serial Bus (USB)
- Provides 4 DB-9 Connectors
- Baud Rate from 75 bps to 921.6Kbps
- 512-Byte Deep FIFOs for each Port
- With the USB Plug-and-Play feature, the system will recognize the device and install the drivers automatically.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B004ET6R50 |
| Best Sellers Rank | #301 in Serial Adapters |
| Brand | SerialGear |
| Color | Black |
| Compatible Devices | Devices with RS-232 DB9 female serial ports such as printers, modems, CNS machines, PLCs, radios, etc. Compatible Devices Devices with RS-232 DB9 female serial ports such as printers, modems, CNS machines, PLCs, radios, etc. See more |
| Connector Type | DB9, USB Type B |
| Customer Reviews | 5.0 out of 5 stars 7 Reviews |
| Finish | Matte |
| Finish Type | Matte |
| Input Voltage | 5 Volts (DC) |
| Item Weight | 1 Pounds |
| Manufacturer | SERIALGEAR |
| Mfr Part Number | USBG-BAY4 |
| Model Number | USBG-BAY4 |
| Number of Items | 1 |
| Number of Ports | 4 |
| Package Quantity | 1 |
| Power Plug Type | No Plug |
| Smart Home Compatibility | Not Smart Home Compatible |
| Specific Uses For Product | Connecting 4 legacy serial devices to modern host systems |
| UPC | 729440626976 |
| Unit Count | 1 Count |
| Warranty Description | 1 Year |

## Product Details

- **Brand:** SerialGear
- **Color:** Black
- **Connector Type:** DB9, USB Type B
- **Specific Uses For Product:** Connecting 4 legacy serial devices to modern host systems

## Images

![USB to Serial 4 Port DB-9 RS-232 Adapter with FTDI Chip - Image 1](https://m.media-amazon.com/images/I/51LX2CLHguL.jpg)
![USB to Serial 4 Port DB-9 RS-232 Adapter with FTDI Chip - Image 2](https://m.media-amazon.com/images/I/61HFp04UgBL.jpg)
![USB to Serial 4 Port DB-9 RS-232 Adapter with FTDI Chip - Image 3](https://m.media-amazon.com/images/I/61IqW+dfwfL.jpg)
![USB to Serial 4 Port DB-9 RS-232 Adapter with FTDI Chip - Image 4](https://m.media-amazon.com/images/I/61sE5p6JSpL.jpg)
![USB to Serial 4 Port DB-9 RS-232 Adapter with FTDI Chip - Image 5](https://m.media-amazon.com/images/I/61RVBJwGtGL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Excellent 4 Port USB to Serial Adapter
*by C***M on February 25, 2012*

Uses the FTDI 232RL chipset with support for the chipset's full RS232 performance, 300bps to 921.6Kbps. Compatible with Linux, MacOS 8, MacOS 9, MacOS X, Windows XP, Windows Vista and Windows 7. Also, works with 64bit versions of the OSes listed that support 64bit. It worked in Linux with 2.6 to 3.x kernels and Windows 7 without the need to install drivers. Windows XP was able to download the drivers. Drivers are provided on the included CD and newer drivers are on their site. The device is small and works well. This device is awesome, but I have two complaints. 1) The ports are close together so it is hard to use some connectors next to each other. 2) In Linux once a port was accessed, if I unplugged the device and connected it again, the ports that have been accessed can no longer be accessed. Ports that were not accessed previously can be accessed until the next unplug and replug. A restart fixes the issue. I imagine this is more related to the driver that my Linux OS was using and/or there may be a method that can allow access again without a restart that I have not found yet.

### ⭐⭐⭐⭐⭐ Pro grade
*by A***R on April 29, 2014*

This is not your cheap, plastic adapter. This is well built of metal and shielded with a good chip set. For that you have a fairly large piece of equipment that is larger and heavier than most other similar products. It works as advertised and is RF proof for use in radio applications. I had no problems with my Windows 7 machine. Drivers worked with no problem and 4 comm ports were created in the OS. You can use external DC power, but it will take power from the USB buss easily enough.

### ⭐⭐⭐⭐⭐ This is by-far the best 4-port USB to Serial Adapter made!
*by B***S on December 15, 2013*

I have been using the SerialGear 4-port USB to RS-232 Serial adapter for about 9 months now. I use it for amateur radio applications where it is exposed to moderate levels of RF. It is well known that the FTDI chipset is superior to any other for radio control applications. The all metal enclosure properly shields the internal PCB from RF. I would recommend this to anyone needing a multi-port USB to Serial adapter, and especially to those working around RF. Brad, KA3YAN

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*Product available on Desertcart Poland*
*Store origin: PL*
*Last updated: 2026-05-25*