Pipe Clamp to suit 1¼" (1.1/4")/1½" (1.1/2") Pipe to BS EN 1451-1:2000/BS EN 1329-1:2000 Size: 1¼" (1.1/4")/1½" (1.1/2") Standard: BS 6798:2009 and Building Regulations Approved Document H Please Note: Pipe Clamp has connection for 19/23mm pipe to receive discharge from condensing boiler