KRISS Super V 30 kit quickly converts your Glock 21 magazine to hold 30-rounds. Easy to install, no tools required. Fits G21 and G21SF magazines. Please note: 1st generation, non-full metal lined Glock 21 magazines (circa 1995 and older), will have occasional functional issues that can cause the follower/spring assembly to hang up as the magazine unloads. Best results will come from using the newer generation G21 magazines, with the full metal lining. Available for shipment to all 50 states.