Choate Tool 20 Ga Sling Loop Base Clamp20 Gauge. Sling Loop Base Clamp (Blued). This Swivel Hardware from the great people at Choate Tool is a 20 ga. Sling Loop Base Clamp (Blued) that is sure to please. This Choate Tool 20 Ga. Sling Loop Base Clamp (Blued) is made using incredibly long lasting and reliable materials that are guaranteed to be more than durable. Choate Tool 20 Ga. Sling Loop Base Clamp (Blued) gives support to your extension and gives a solid attachment for a sling. Don't own a weapon without the Choate Tool 20 Ga. Sling Loop Base Clamp (Blued). Specifications for Choate Tool 20 Ga Sling Loop Base Clamp: Manufacturer: Choate Tool Finish: Blued Country of Origin: USA Features of Choate Tool 20 Ga Sling Loop Base Clamp 20 Ga. Sling Loop Base Clamp (Blued) Package Contents: Choate Tool 20 Ga Sling Loop Base Clamp Choate Tool CMT-55-08-07: 20 Ga Sling Loop Base Clamp20 Gauge