2pcs butterfly hinge clamp durable practical fixation frame metal silk printing

these screen printing hinge clamps are fabricated from iron metal, surface plated color, durable in use. feature a wide-wing thumbscrew for firmly fastening the clamp to the frame. these clamps also feature positive locking for perfect registration. easy to screw it on any flat surface and a loose pin permits quick screen removal. these butterfly clamps are used for fixing screens when printing, it is u