The Monstro-Coupler 2.375 perfectly connects to 2" pipe.(2.375" OD) The Monstro-Coupler 2.375 has a 1/2"- 13tpi countersunk fastener for connecting a fixture. The Monstro-Coupler 2.375 is CNC machined from 6061T-6 aluminum alloy and has a working load limit of 1100 pounds.