83Y149 Transistor & Diode Checker Checks leakage-to-gain ratio and noise level of junction, point-contact (that's a collector item!) and barrier transistors. Checks germanium and silicon diodes, forward and reverse current conduction of selenium rectifiers, continuity and shorts. Has Leakage-Gain switch; forward current control; calibration control. Separate sockets for NPN and PNP transistors. Battery operated. Weight: 2 lbs