---
product_id: 79232739
title: "iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21)"
brand: "istarusa"
price: "958 zł"
currency: PLN
in_stock: true
reviews_count: 5
url: https://www.desertcart.pl/products/79232739-istarusagroup-mini-itx-box-fit-1u-flex-s-21
store_origin: PL
region: Poland
---

# Supports 2x 2.5" or 1x 3.5" HDD for versatile storage Strategic side ventilation for optimal cooling Compact Mini-ITX motherboard compatibility (6.7" x 6.7") iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21)

**Brand:** istarusa
**Price:** 958 zł
**Availability:** ✅ In Stock

## Summary

> 🖤 Power-packed performance in a sleek, space-saving chassis

## Quick Answers

- **What is this?** iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21) by istarusa
- **How much does it cost?** 958 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/79232739-istarusagroup-mini-itx-box-fit-1u-flex-s-21)

## Best For

- istarusa enthusiasts

## Why This Product

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

## Key Features

- • **Mini-ITX Ready:** Perfectly sized for 6.7" x 6.7" motherboards, maximizing power in minimal space
- • **Sleek & Compact Design:** 1U form factor with a slim 8.9" x 3.5" x 8.3" footprint fits any professional setup
- • **Flexible Storage Options:** Choose between dual 2.5" drives or a single 3.5" HDD to fit your workflow
- • **Optional 80mm Fan Support:** Add active cooling when you need that extra performance edge
- • **Effortless Cooling Mastery:** Side vents engineered to keep your system cool under pressure

## Overview

The iStarUSA Group Mini-ITX Box Fit 1U Flex (S-21) is a compact, versatile 1U chassis designed for Mini-ITX motherboards (6.7" x 6.7"). It features strategic side ventilation for enhanced cooling, supports either two 2.5" or one 3.5" hard drives, and offers optional 80mm fan installation. With its slim dimensions (8.9" x 3.5" x 8.3") and lightweight 3-pound build, it’s ideal for professionals seeking powerful performance in a minimal footprint.

## Description

iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21)

## Features

- Strategically Placed Side Ventilation Aid in Cooling
- Accommodate either 2x 2.5" or 1x 3.5" HDD
- Motherboard Size: 6.7 x 6.7 (mini-ITX)
- Optional Fan: 1x80mm
- Dimensions (WxHxD): 8.90" x 3.50" x 8.30"

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Number of USB 2.0 Ports | 2 |
| Brand | iStarUSA |
| Series | iStarUSA Group Mini-ITX Box Fit 1U Flex (S-21) |
| Item model number | S-21 |
| Item Weight | 3 pounds |
| Product Dimensions | 9 x 9 x 4 inches |
| Item Dimensions  LxWxH | 9 x 9 x 4 inches |
| Color | Black |
| Manufacturer | iStarUSA Group |
| ASIN | B0077CRF6Q |
| Is Discontinued By Manufacturer | No |
| Date First Available | February 9, 2012 |

## Product Details

- **Brand:** iStarUSA
- **Motherboard Compatability:** Mini ITX
- **Case Type:** Mini-Tower
- **Recommended Uses For Product:** Business
- **Color:** Black
- **Material:** Alloy Steel, Aluminum
- **Power Supply Mounting Type:** Side Mount
- **Cooling Method:** Air
- **Model Name:** iStarUSA Group Mini-ITX Box Fit 1U Flex (S-21)
- **Item Weight:** 3 Pounds

## Images

![iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21) - Image 1](https://m.media-amazon.com/images/I/31sB2bmFMKL.jpg)
![iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21) - Image 2](https://m.media-amazon.com/images/I/41yBikSm+-L.jpg)
![iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21) - Image 3](https://m.media-amazon.com/images/I/41uD5J80LxL.jpg)
![iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21) - Image 4](https://m.media-amazon.com/images/I/318IG10pYML.jpg)
![iStarUSAGroup Mini-ITX Box Fit 1U Flex (S-21) - Image 5](https://m.media-amazon.com/images/I/41eFO7i16BL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Nice little itx case.
*by D***. on April 18, 2018*

i3-8100GIGABYTE Z370N WIFISamsung 960 EVO Series - 250GB PCIe NVMe2X HGST Travelstar 0S03563Noctua NH-L9IFSP Group Flex ATX 220W 80 PLUS CertifiedNice little itx case. All steel case with plastic bezel. Plenty of room on the inside for wire management without it being too cramped. No issue with clearance of M.2 NVME ssd on the back of the motherboard and the motherboard stand offs giving you plenty of room. I was looking for a case for a low power/heat build that I could put into a dusty environment and this seemed to work. I found the flex ATX power supply to be cheaper then that of a pico psu with the power brick on top of it. Most other itx cases that did come with power supplies were very under powered and flaky for what I needed. Also make sure you get a 4pin to 8pin atx adapter if you tend to use newer mother boards,one bad thing about this case is that I doesn't come with any feet though I just used some furniture felt pad feet

### ⭐⭐⭐⭐ Great case.  Using it for pfSense.  Airflow could be improved.
*by C***L on May 6, 2018*

Pros:- It is tiny! It is about as small as is possible with the component compatibility it has.- It is rugged. For the $55 I paid for this I was expecting it to feel more like other cheap stamped cases I’ve used. However, this thing has a military-grade feel, especially the front panel.- The top of the case lifts off to add/remove components. It comes with 3 screws: 2 philips heads and 1 thumb screw. The way this panel slots in makes the philips screws optional, so it allows you to decide if you want something tool-less or more tamper-proof.- Uses a proper server power supply form factor (very hard to find in non-rack mount cases)- Space for an expansion card (very hard to find in this size case)- Available mounting accessories. You can buy wall-mount of vesa mounting parts for about $10 which allow this case to be put almost anywhere.Cons- Airflow. The front 80mm fan in the front has a very restricted inlet, the design of the front panel blocks most of the available air. This would be an easy design change, and I find the decision to obstruct the only usable intake to be very confusing.- Airflow again. The side 60mm fan conflicts with the PCIe slot. The product page says you could put a thin (10mm) fan here but even that would block the PCIe slot. If you’re not using the PCIe slot then you could easily fit a standard thickness fan.- Cooler height. My build uses an Intel Pentium G4560 which comes with the smallest intel stock cooler. Even that cooler was about 5mm too tall and would conflict with an expansion card. I ended up using a Noctua NH-L9i which is just 37mm tall and you really couldn’t go any taller with an expansion card installed.- Drive Mount. In my build I decided to use an m.2 drive, which I’m very glad I did since the drive mount on the top panel interferes with the front 80mm fan. This means that if you want to mount a 2.5” hdd/ssd you can’t mount a front fan, which makes the case useless. Also since, there are no ventilation holes on the underside of the case, I wouldn’t want an itx motherboard with an rear m.2 slot (as many do) and would only pair this case with an itx board with a top m.2 slot.- Doesn’t come with rubber feet, which are required to not damage any surface you set it onto.- You will need a PCIe riser cable (not included) in order to use the expansion slot.What would make it 5 stars:All it would take to make this 5 stars would be to put 2x 80mm fan mounts on the front of the case with a more open inlet (bonus if there was a filter), add more ventilation holes on the back, and move the top drive mount 10mm further back. Those are all tiny changes, but would make this case infinitely better.I’ve still given it four stars because it is so nicely built and because there are no other cases that really compete with this one.

### ⭐⭐⭐⭐⭐ Great case, very durable
*by A***5 on October 31, 2018*

Case is fantastic. Very sturdy feeling, much more rugged than any other PC case i've used. Currently using Silverstone FX350-G power supply (350W Gold Rated) and had to modify case slightly to get it to fit. Case was able to fit Wraith Spire cooler (70mm height), but had to remove the hard drive bracket to get it to fit. Also as others have noted, the case may scratch your desk if you slide it around, so make sure to be careful of this.

## Frequently Bought Together

- iStarUSA Group Mini-ITX Box Fit 1U Flex (S-21)
- Noctua NF-A8 PWM, Premium Quiet Fan, 4-Pin (80mm, Brown)
- Noctua NF-A4x20 PWM, Premium Quiet Fan, 4-Pin (40x20mm, Brown)

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*Product available on Desertcart Poland*
*Store origin: PL*
*Last updated: 2026-05-28*