CZ Custom MecGar CZ 75 3 Round Magazine Extension Black. Pads are made of aluminum with factory spring and follower will hold 20rounds 9mm. With CZC 10 coil spring and follower fit ( will hold 22-23 some modification will be needed to follower). Specifications for CZ Custom MecGar CZ 75 3 Round Magazine Extension: Manufacturer: CZ Custom Color: Black Fabric/Material: Aluminum Magazine Capacity: 3 Round Caliber: 9mm Luger Gun Make: CZ Gun Model: CZ 75 Gun Type: Pistol Package Contents: CZ Custom MecGar CZ 75 3 Round Magazine Extension What firearm models does the manufacturer say CZ Custom MecGar CZ 75 3 Round Magazine Extension is compatible with? The manufacturer suggests that CZ Custom MecGar CZ 75 3 Round Magazine Extension is compatible with CZ 75CZ Custom 10433: MecGar CZ 75 3 Round Magazine Extension Black