Watch the Informational VideoThe Cylinder & Slide Glock Ambidextrous Magazine Release is a drop in part that fits 1st, 2nd and 3rd GEN model 9mm/40 caliber Glocks. The factory wire magazine catch spring must be replaced with the included extra power magazine catch spring. The ambidextrous magazine release cam on the right hand side of the pistol does not interfere with right hand use of the pistol.