Premium ABS Material These Boston air valves are made of thickened ABS material, durable, odorless, lightweight, portable, anti-rust, anti-corrosion, and resistant to aging, ensuring long-term use. Anti-Leakage Design The bottom of our spiral air plugs features an air cushion design to prevent air leakage, providing a secure fit and reliable protection for your safety. Ideal Valve Replacement These anti-leakage air valve bungs are an ideal economical choice for replacing air valves. The screw plug opening size is 20-22 mm. Please confirm the size before purchase. Quickly Inflate and Deflate Easy to use, allowing for quick inflation and deflation (one-way inflation) by simply attaching the inflatable boat air valve to the inflation port, offering added convenience. Wide Application These Boston spiral air plugs are suitable for most rubber dinghies, hot tubs, airbeds, inflatable boats, rafts, and other inflatable products. The Boston air valve is an essential accessory for water enthusiasts.