Material: These couplings are made of high quality plastic material, which has good strength and stiffness to withstand large loads, they also have good abrasion and heat resistance to ensure the most reliable leak free connections Wide Application: I Type 1/4" inline check valve for RO pure water reverse osmosis system Quick Install: These quick connect fittings use push-in technology for easy installation and removal and require no tools Features: Reverse osmosis one way non return check valve. Allows flow in only one direction only Package: 5 Pcs Straight Push Connectors; Tube O.D. : 1/4" x 1/4", Manufacturer: PXYELEC