The falcon eyes cbh-1 clamps can be used in conjunction with 2 light stands and a crossbar to build a complete background system suitable for 1 background. additionally, the cbh-1 clamps can be used to expand an existing background system by adding an extra background roll or cloth.the copper pin is 53mm long and has a diameter of 10mm. the clamps fit on tubes with a maximum diameter of 35mm. the distance from this tube to the pin is 66mm long. the clamp is fixed with a screw and the copper pin can be exchange with spigots (3/8” male thread), allowing you to mount extra lamps on the bracket. the clamp is equipped with rubber, minimizing the chance of damaging your light stand.