The innovative DW Claw Hook Clamp is designed for securely attaching a variety of percussion items to almost any bass drum. The clamp grabs the bass drum hoop from both sides of the hoop, avoiding slippage that occurs with most traditional bass drum clamps. The included L arm with memory lock is 1/2" to 10.5mm, however a variety of arm diameters may be inserted in the sturdy, welded V-clamp. Perfect for adding cowbells, tempo blocks other percussion instruments to your set-up.