This magazine extension adds 3 rounds to your 10-round CR920 magazine making it a 13-round magazine identical to the one included with the gun.
 
The CR920 was designed with an extra powerful magazine spring from the very beginning so you do not need a different magazine spring when converting a 10-round magazine to to a 13-round magazine.
 
Complete drop-in assembly (front section, rear sections, locking pin).
Fits only CR920 Magazines.