Get your boost back and get Full Performance From Your Turbo! This boost leak tester is designed to fit over the inlet flange of your turbo charger and allows you to pressurize the charge system with compressed air while the vehicle is off. This is an important tool every turbo car owner needs in their arsenal of tools. It will keep the turbo healthy by eliminating leaks in the boost path and not allowing it to over speed compensating for a boost leak. A must if you are tuned or any time you are replacing any components in the intake tract such as charge hoses, intercooler, manifold, vac lines, injectors…etc. Also a must if you are going to the track and want the peace of mind that the turbo wont over-work or risk blowing any hoses off that are loose Why have the Gauge? Not having a gauge readout on a boost leak test is similar to filling air in your car's tire without a gauge. You just don't know how much air is in the system! It's wise to know how much pressure is actually going into the charge system to prevent damage to the engine and to yourself. For example, if the compressor is unregulated (ex. shop air at 90 PSI) there is a risk that you can over-pressurized and something will give. Benefits of Gauge: 1. Allows you to apply a safe amount of pressure to prevent injury or damage 2. read how fast the system holds and bleeds air 3. Gives a good comparison of compressor outlet air Vs. boost test air while pressurizing. (lower the difference the better) 30 PSI range will give you the appropriate reading when testing your charge pipes for low, medium or high boost levels.