Amazon.com: O-Ring Attachment For I-Beam;Stainless C Clamp With O-Ring;Beam Clamp With O-Ring, Metal Clamp Hook.That Can Withstand 50 Pounds Of Static Gravity (6Pack)
Clamps, Rings & Rims: Face Clamps, Lens Holders, V-Band, Band Clamps, Mounting, Dial, Lighting Ring, Adjustable, Aluminum, Lends Holder