1. electrical contact pressure gauge 2. 60mm,100mm,150mm 3. -0.1 ... negative pressure of liquid, gas or vapor not corrosive to copper, steel and alloy, and sends signal or connects control circuit ... negative pressure of liquid, gas or vapor not corrosive to copper, steel and alloy, and sends signal or connects control ... or brass Aluminum PC lens, glass lens YXC-100 electrical contact pressure gauge