||I bought this for the SR25 gearbox I'm building from the ground up and it seems to be working very nicely. I have it installed in a Matrix Ver. 2.5 gearbox and despite the ribbing on the outside it fits well. It has great compression with the cylinder/piston head I'm running. So good in fact that I can't even compress the piston half-way.
The only negative thing I have to say about this cylinder is it will NOT fit in an A&K SR25 gearbox shell unless you dremal the cylinder window, which I didn't even want to waste time on.
Does what it's suppose to
Ribbed(can be a con also)
A bit pricey
Again it's ribbed
will not fit in an A&K SR25 gearbox shell
Rating: [4 of 5 Stars!]