Separate straps hold round objects up to 381mm in diameter, Holds equipment measuring up to 711mm in linear distance, Each clamp supports a safe working load of 150lbs. (68 kilos) with a break-strength of 300lbs. (176 kilos). Two clamps support 300lbs with a break-strength of 600lbs (272 kilos), Each half of the clamp mounts with four #10 screws or bolts