Pearce Grip PG26G4 Grip Extension made of Polymer with Textured Black Finish & 1" Gripping Surface for Glock 26, 27, 33, 39 Gen4-5 $6.40
Kriss USA KVAMX2K90BL00 Mag-Ex2 Extension Kit Extended 9mm Luger 40rd Compatible w/Glock 17 Gen3-5 17rd Magazines Black Polymer $32.99