Our Kit is designed for use with Freightliner, International, Kenworth, Peterbilt, Volvo, GMC and Sterling cooling systems Use shop air to maintain constant pressure to the cooling system during testing and refill Helps eliminate the complications often experienced with unreliable rubber plugs or bladders, saving setup time and providing more accurate test results Quick Disconnect vacuum attachment allows rapid refilling of the cooling system Includes Heavy Duty Vehicle adapters, pressure test regulator, vacuum refill attachment with tubing, all in a durable storage case