a Holds objects from 5/8" to 1 3/8" (16 to 32mm) in diameter. a Each clamp supports a safe working load of 25lbs (11 kilos). a 2 clamps support 50 lbs (23 kilos). a Mounts easily with one #10 bolt. a Mounting area: 1 1/2" x 1 1/2" (38 x 38mm)