For 3/4" to 1" diameter rails 316 Stainless steel tube and clamp with plastic inner liner Rotates 360 degrees to desired angle while mounted Self draining Rod holder diameter: 1.5" Description These durable and functional fishing rod holders clamp easily on to your boat with no need for drilling. They fit nearly any rail, 3/4" - 1" in size. The rugged stainless steel won't corrode while the rubber inner liner protects your rods. The screw mechanism allows the rod holder to be adjusted easily to the desired angle. Self draining.