Our durable aluminum adjustable boat covers support poles protect your boat by preventing rain water from pooling on top of the boat cover, tarp or pontoon boat cover you use. This sturdy telescoping boat cover pole support is made from marine-grade materials and comes with 2 tops, 1 is a rubber cap style with snap and the other is a mushroom cap with slits that can be used with support straps (not included), making these boat cover support poles adjustable versatile and able to work with the different styles of boat covers. We proudly stand behind the quality of all our products! We are a family owned American business committed to making premium quality products.