Features: This adapter is used to prevent freezing of garden hoses, sprinkler systems, faucets and travel vehicle water lines such as RV/camping/boat/travel trailers that drain water from water lines/pipes or pipes. Use simple and convenient antifreeze methods to help reduce the use of antifreeze. Adapters are standard threaded connections in most cases. Easily connect air lines to water lines or hose systems, making it the perfect winter solution. Made of brass, this adapter is sturdy, durable, very safe, not easy to break or deform, and will serve you longer. Twist the water tube to the female side, connect the quick plug to the quick connector inside the air compressor line, then turn on the air compressor and turn it around the rod to turn it on or off and adjust the air flow rate to dry the water from the water tube. This adapter works with many systems (such as RVs, campers, boats, travel trailers, etc.), vehicles with plumbing systems. Specifications: Material:Brass Size1:Approx.8.48x2.65cm/3.33x1.04inch Size2:Approx.8.2x3cm/3.22x1.18inch 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. Thanks for your understandings. Package includes: 2x Brass Ball for Valve