This is a great Magazine pouch and will fit the Glock 21 Double Stack mags (in 45 ACP). Note that there is no belt loop for fastening onto a belt. The back of the mag pouch is completely covered with the hook material for securing the mag pouch to a vest with the loop material that would be already on the vest (or any other product that has the loop material).
Pros: Hook & Loop Closure instead of snap, material is nylon
Cons: No Belt Loop
This review was written in the old system and had content requirements that are different than reviews written today.