The Falcon Eyes Clamps CBH-11, size: 11.5 x 10cm which combined with two light stands and a crossbar make a complete background system which is suitable for one background role. These clamps can also be used to expand an existing background system with an extra roll or cloth. This makes the clamps suitable for use on location, but also for use in your studio. You can tighten the clamps on stands or pipes with a minimal diameter of 15mm and a maximum 40mm. You can place crossbars ore pipes with a maximum diameter of 50mm. In the side of the clamp is a 3/8 female thread, which ables you to extend through a spigotadapter a numerous extensions to your background system. These robust and strong clamps are durable and therefore can be used in combination with the heaviest paper rolls or rolls of vinyl.