Things I liked:Everything (Co2 and BB's) are contained in the mag. The size and weight of the mag adds to realism for training purposes. Things I would have changed:The valve/seal that accepts the Co2 cartridge is threaded counter to the natural clockwise rotation of the C02 cartridge as its being screwed in. The result is that the valve/seal unscrews as the C02 is tightened. Should have included a proper tool for keeping the valve/seals tight, as a flat-head screwdriver is a bit awkward. What others should know:The valves/seals need to be tightened every so often or they will eventually leak.
Things I liked:Very well made. I put this on my Umarex EBOS. I was worried about it being tall enough to get over the BB hopper at the end of the gun. It works like a charm. No riser or extension required. I'm very happy with the result. Things I would have changed:Nothing What others should know:Works right out of the box with Umarex EBOS.