describe 【Conversion Adapter】 The pool hose adapter is used for the salt water system of the above ground pool. If you only have a 1.25" hose but want to install a 1.5" piston valve or upgrade to a more powerful filter pump, the A adapter is the perfect solution. 【Compatible】 Pair of A series adapters, 25007. Fits all 4000, 2500, 2000 and 1500 GPH filter pumps with Intex threaded hose connectors. 【High Quality Material】 The pool parts are made of high quality plastic material, strong and durable. The rubber ring is tightly connected to the 1.25 inch hose to form a sealed space to prevent water leakage. 【Easy to Install】Hose adapter A is designed to connect a 1.25 inch hose with a piston valve or filter pump. The small end connects to a 1.25" tube. The threaded end connects to a 1.5" piston valve or strainer pump and simply tightens. Saves additional costs by not having to purchase another size hose.