MINIFOCUS 6" Double Ball Aluminum Extension Arm, 1" Ball Head Connector Underwater CNC Arm System Ball Head Extension for Strobe/Video Light/Diving Camera Tray, Waterproof and Rustproof (2pack)

I've been diving with these on my compact camera rig for several months and they seem to work just as well as the pricy Ultralight arms I have on my mirrorless rig.

Decent design at a good price. Hope they last. Hard to tell with cast metal products. They work right up to the point they fail.

Great product quick shipping

The arm itself seems pretty solid but the o-rings that came with the arm started to immediately disintegrate when put into a ULCS clamp. As a test, I pulled an o-ring off a ULCS arm and it fitted with no issues and seemed to hold up much better, most likely due to being a much harder material. Luckily, you can purchase replacement o-rings for cheap so I went with the Buna-N 209, pack of 100 for $11. Will update review if there are any additional issues.

I bought these to use with RAM mounts on my motorcycles for give more variety of GoPro angles.They do work with the RAM system, but I'm not impressed with their grip strength. The RAM ball mounts have some sort of rubberized coating on them that makes them quite grippy and resistant to slipping. These however just have a single o-ring running around the diameter which provides very little grip. I find they slip quite easily no matter how tight I make the clamp.If you're not doing anything that has a lot of vibration or movement, they're probably fine. The arm itself is nicely cast from aluminum and appears quite durable. I just wish they had gone the extra mile and used the rubberized ball ends like RAM does.