20BPG-50 (05703159): B-Series Pressure Murphygage 20DP Differential Pressure Swichgages These units are for negative

These units are for negative ground

The tachometer is for negative ground or isolated electrical systems

EGS21P-80-12: Electric Pressure Swichgage

Polycarbonate

Sensing Bulb: Copper*

20BPG-50 (05703159): B-Series Pressure Murphygage 20DP Differential Pressure Swichgages These units are for negativeThe 20BPG 50 B Series Pressure Murphygage is a high quality, diaphragm actuated indicating gauge, with a pressure range of 0 50 psi. Built with the same heavy duty design as the standard 20 Series Swichgage instrument, the B gage is more compact and is the optimum instrument for gauge only applications. The 20BPG 50 has a high impact polycarbonate lens, a sturdy environmentally sealed steel case, and a polished, low profile stainless steel bezel.