Function: Fluid line stoppers can prevent liquid contamination or leakage during maintenance, and minimize the risk of using the hydraulic system during work. Easy to Use: Designed to preserve the integrity of hydraulic oil or fluid when repairing and changing vehicle plumbing systems. Easy to use and easy to operate. Seven Pieces Set: Our set includes four sizes of fluid stopper 1/2 inch, 3/8 inch, 5/16 inch and banjo stopper, also with 3 yellow plugs, is enough for long term car maintenance. High Durability: The tool is made of durable ABS material, which is resistant to high temperature, high pressure, etc., and can be reused many times. Wide Application: The set is suitable for most models of pipe system maintenance and repair. It can be used to stop the movement of brake fluid, water, gas, chemical and other fluids.