The KSM30A 30 Ampere DC Moving Coil Ammeter is a smart-looking monitoring instrument for HHO systems. It is simple to install, light weight and, unlike digital ammmeters, requires no additional isolated power supply .
Quality,rugged damped movement
Integrated 30Amp shunt (very cost effective)
Face Size; 58mm Wide 52mm high
Mounting Hole: 45mm diameter