Pearce's Plus Extension grip for the Glock 42 replaces the magazine floor plate providing one extra round of capacity. It is approximately 3/4" additional gripping surface for better control and comfort while also incorporating the factory texture pattern.A magazine extension grip for the Glock 42 (380 cal). This extension replaces the magazine floor plate providing one extra round of capacity and approximately 3/4 inches additional gripping surface for better control and comfort while also incorporating the factory texture pattern.