Adapting your current or future manual or electric air pump to fit Fendertex fenders, the Fendertex Air Pump Inflation Adaptor fits many available options on the market. The supplied hose adapter is an HR style (also known as a twist lock) and has approximately 7/8in outside diameter. Various sizes of spacers come with different thicknesses for better fit. Fendertex products will use both black and yellow spacers, while other products may use the green. A small screw at the center of the adapter must be tightened all the way before use or removed entirely. This adaptor kit is a great option for fenders or even inflatable boats and paddleboards among many other pieces of gear.