At only 7 lbs. and only 9" tall, the Mac Tools Leak Attack Diagnostic Leak Detector is easy to use both under the hood or under the vehicle. Diagnose leaks with shop air using flow measurements or pressure decay (leak down). Thick "smoke," produced using mineral oil, quickly pin-points the leak location to speed diagnosis and repair. A final leak down test quickly confirms a complete repair eliminating comebacks. The air-safe design does not use a glow plug and eliminates the need for expensive and bulky nitrogen cylinders.