A&G Magazine Spacer GLOCK 20/21 to 29/30 Black.
Lets you use a Glock 20 magazine comfortably in a GLOCK 29 or a GLOCK 21 magazine in a GLOCK 30.
Slip-on collar, fills the space between a compact frame and bottom of a full-sized magazine to make a comfortable, hand-filling grip. Contoured to match the frame for improved trigger and recoil control. Ideal when using full-size magazines as backup.