Column Clamp Base Accessory for allowing splitting or redeploying KXC, K1C or K2C arms onto additional Column Desk Mount. Spare Column Desk Clamp Base Accessory for splitting or redeploying KXC, K1C or K2C arms onto additional Column Desk Mount Requires KXC, K1C or K2C Column Mount Arms - Column Mounting Interface Includes Column Cap, Installation Tools and Bolt-thru Mounting Kit