Strike Industries Modular Magazine Release, Fits Glock 17/19/22/23/26/27/31/34/35 Gen 1-3, Black SI-G3-MagRelease-BK The Strike Industries Mag Release for the Gen 1-3 GLOCK is a new modular upgrade for a compatible GLOCK Gen 1-3. Included are two push buttons that are easily interchangeable. Both button faces are CNC milled from 6061 Aluminum" with mag release internal mechanism made from high density polymer that provides smooth ejection.