Key Features Genuine Evolution Aqua Fittings Made of Flexible rubber Easy to fit and adjust with 2 jubilee clips per fitting Connects any type of pipework Reusable, simple to remove or move when needed. No Gluing required. Sizes range from 1.5" to 4". Suitable for large Koi systems like the Evolution Aqua Nexus. Evolution Aqua Flexible pond fittings are a perfect solution for all your pond equipment needs. The rubber fittings, known as “Boots”, are made of strong and durable rubber that has been designed to fit easily onto various types of pipe from PVC to lead, Copper to clay. Each fitting has an easy to adjust jubilee clip on each end, making connection simple and gives a perfect seal with no need for gluing. The fittings can then be removed and reused over and over again and can be adapted to any pond system set up. The reducing adaptors are ideal to connect pipework or tubing of varying sizes.