Cross Armory Glock Extended Magazine Catch increases magazine changing speed, thumb feel and ergonomics. Does not interfere with the holster. It is precision machined from the strongest made 7075 T6 Aircraft Aluminum. It is then anodized or metal coated (Titanium Nitride or Nickel Boron) for improved finish and corrosion resistance.Fits Glock 17/19/22/23/24/26/27/29/31/32/33/34/35 Gen4-5.