5X Periscope HD Monocular Portable Monoculars Periscope, Adjustable 20" to 27" Observation Telescope for Bird Watching Hunting Hiking Concert Travelling

I bought it to be able to watch my two high schoolers bowl at crowded tournaments. Since most bowling alleys are typically not set up to favor the spectators, this periscope has allowed me to see shots when the players and coaches are all standing in front of the lanes. It is sturdy, came with a nice case, is simple to use, and works just like I expected. It isn't bulky to haul around nor is it really delicate that I worry about using it. Lastly, the list of uses on the package of this periscope made me laugh since I just pictured some random person running around looking around corners, which then creeped me out a bit. 😂 (See photo above for entertainment). I have already recommended it to other bowling parents, struggling to see their children's shots.

It works but is not as clear as i had hoped

I supposes you get what you pay for. I personally find this thing to be mostly useless. The field of view is awful, the adjustment knob on the ocular lens doesn’t really do much of anything. It’s a novelty, it isn’t in any way good optical equipment. Again, you get what you pay for. The marketing hype for this thing simply doesn’t deliver in real life use.

This thing is pretty cool. I like to watch what my dog does when he first gets to daycare but the fence is high. Now I can see right over it, clear as can be.

I purchased two of these to experiment with building a hyperstereo binocular setup (using a wide separation for enhanced depth at long distances). The units work, but I noticed a slight ghosting effect on bright objects. This appears to be related to the prism coatings. For my purposes, that became noticeable during high-contrast viewing. If you’re planning to mount two together, be aware that alignment takes patience. I used photography cheese plates and clamps to build an adjustable frame. Some minor mechanical modifications were needed for proper alignment, including adjusting threaded mounting holes and rotating one barrel slightly to achieve vertical alignment. This product can work for experimental or DIY optical projects, but precise alignment is important.

Works as it should

This periscope is awesome. We go to tons of Bowling events and the college teams stand the whole time that they are playing. With the periscope we can see each throw. It is so cool.

It's good overall and I can adjust my eye relief just fine. Works in bright and low light levels. The only issue I have is the silver aluminum piece from the photo popped out from somewhere on the extender I believe. I just got it the day before. Everything still works except I think it might of been a break cause instead of the being a few mm gap when the arm is completely lowered, there's no gap now and it'll slam into the top of the monocular. So over time I worry it might crack the glass. It should be an easy fix but I haven't for the life of me figured out where it popped out of.