The Slug Plug fits all full size and compact Glocks. G-17,19,21,22,23,24,25,31,32,33,34,35 & 37. The Slug Plug keeps dirt, debris, dust, rain and snow out of your Glock as well as providing more positive and faster mag changes. I have a brand new plug that has never been used, still in original package that I dont need. $5.00 should cover postage and envelope.