The CT8002 is a computer safe, all solid state electronics circuit tester. Unlike regular test lights, this high-impedance circuit tester is safe to use around automotive computers, ECM/ECU/PCMs, electronics, sensors and air bags.; Rugged, built to last and simple to use, it requires no wire or clip connector to ground. The CT8002’s LED, sound and vibration indicators, allow users to check for power in less time that it takes to set-up a regular test light and find a suitable ground, and is designed for use in automobiles, trucks, tractors, trailers, RV’s, motorcycles, boats and any DC powered circuit from 3 to 28 volts.; Input Impedance: 1Mohm minimum (approx. 20 micro-amps @ 24 volts); Input Voltage: 3 to 28 volts D.C.; Indicators: light, buzzer and vibration indicator; Body: stainless steel construction; Power Source: 1 x AA-size battery; Weight: 60 g (2.2 oz.) including battery; Dimensions: 146 mm length x 15.9 mm diameter (5.75″L x 0.625″dia.)