The OTC Vacuum/Pressure System Tester, No. 6975, is a two-way vacuum/pressure system tester that can diagnose leaks in pressure or vacuum systems immediately, according to the company. The patented design includes an intuitive rotary dial and high quality silicon hoses to allow for easy and quick switches between pressure and vacuum test modes. The hose fittings also assist technicians in making quick hose/adapter setting changes, which are leak-free under pressure or vacuum. For optimal viewing, the integrated rear-mounted gauge tests up to 30 psi pressure and up to 28 in Hg vacuum.