This plug will Fit Glock Models 17, 18, 19, 20, 21, 22, 23, 24, 25, 31, 32,
34, 35 The Backstrap Channel plug was designed to guide the magazine
into the magazine well to stop the magazine from snagging on structures within
the pistol. The secondary function of the insert is to stop dirt and debris from
entering the backstrap channel; this stops the dirt and debris from potentially
interfering with the trigger mechanism.