Choate Tool Remington Base Clamp Mattet. These clamps gives support to your extension and gives a solid attachment for a sling. Specifications for Choate Tool Remington 20 Ga Base Clamp Matte: Manufacturer: Choate Tool Color: Black Country of Origin: USA Features of Choate Tool Remington 20 Ga Base Clamp Matte 20 Ga. Sling Loop Base Clamp (Matte) Package Contents: Choate Tool Remington 20 Ga Base Clamp Matte Choate Tool CMT-55-08-08: Remington Base Clamp Mattet