It uses a detachable “head” for readout and operator input. A single unit can access up to 90 transformer-rectifier controllers through a few simple keystrokes. Our T/R control panel’s head features: a dot-matrix display and tactile, push-button switches mounted in a small, rugged all-environment assembly. The unit can be handheld or panel-mounted. It has a life expectancy of 30 years under normal use.