Matrix Polymer Hopup Component Set - M4/M16

"This is a nice budget hop up gear set, nothing special but it doesn't need to be anything special. The arm that holds the spacer was slightly thick for my hop up unit, which is actually a good thing; it allows you to file it down to securely fit into your hop up. The only gripe I have with this kit is the bucking; it doesn't want to work correctly with my hop ups, but it might work for someone else as it seems like good quality (good enough anyway). Although the bucking didn't want to work correctly, I didn't buy the kit with the intention of using the bucking - I used a different matrix (white) bucking instead and it works well.

"I bought this just for the retaining starlock washers lol i could not find them anywhere online or locally i even checked hardware stores but anyway. This is still nice to have spare parts, i'm still using my old hop up unit because when i bought a rotary i somehow lost 100 fps so i switched back and i somehow lost the starlock washers that hold in the gears.

PROS
spare parts for old gear style hop ups

CONS
bucking is trash
does not include o ring for retention (luckily i had mine)

"Came in as a srs set. Do not expect this to give any advantage to a stock wheel set or bucking. Use this for replacement parts. Add a small o ring under the adjustment wheel screw to add retention. I would not buy this again if I had extra parts laying around.