Slug Plug fits Glock Generation 1-3 Glock models 17, 17L, 19, 20, 21, 22, 23, 24, 31,32, 34, 35, 37, 38 (not for SF models). Grip Plug by LONE WOLF. 

Subdued detailed engraving of POLICE. 

Streamlined, understated, subdued look.