Features: Prevent water leaks, noise, and damp floor caused by backflow valves failures with this check valves and PTFE tape set , ensuring clean water supply protection in black tank flushing systems. strong ABS construction withstands 8 to 125PSI water pressure, featuring 1/2" threads for secure, leak free connection in plumbing systems. Ideal for owners, campers, and trailer enthusiasts needing reliable backflow prevention to replace worn out 571 type check valves. Install vertically between freshwater inlets and tank flushers in travel trailers or motorhomes, maintaining a 6 inch clearance above waste tanks for best performances. Address common black tank flushing issues like clogs and siphoning while complying with safety standards for long term wastewater management. Specifications: Material: ABS Product size: 7.3x5cm/2.9x2in Package Includes: 1xCheck valves with Tape note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.