Pliant and durable The cups are made from UV-stable TPE plastic and are rigid enough to support a jump bar, but flexible enough to bend out of the way on impact. The Heights adjust every 2" from 4" to 26". They also feature large easy to read molded numbers.The clips are designed to clip on jumps made from schedule 40 1" or 1 1/4" PVC Piping. They can be easily adapted however to work with wood and metal jump standards as well.Clip on strips are sold in Pairs of 2 and include fasteners. .