This is a Glock drum magazine with a 50-round capacity/40-round capacity for Glock 9mm pistols/.45 Auto pistols.
RWB drum magazines deliver maximum capacity and impressive quality for the world’s most popular pistols—all at a price that’s hard to beat.
Featuring an all-black polymer construction polymer and steel construction, this drum magazine works with Glock pistols (Gen 3 or later)
Features include heat-treated internal chrome silicon wire spring for maximum reliability and smooth feeding, and special finger taps for quick and easy reloading.