1. Support dual-channel signal input 2. Support 4-speed adjustable frequency, 4-speed adjustable internal resistance 3. B-channel position is adjustable 4. Support A-channel or A+B-channel display 5. Support trigger signal output (5V) High safety: ASA testing does not require the circuit board to be powered on; ASA testing does not involve circuit principles and does not require the circuit to be in working condition. Strong adaptability: ASA testing does not involve the functions of the components on the circuit board, so no matter what type of components the circuit is composed of, including digital, analog, mixed digital and analog, etc., it can be tested. Use DC 5.5*2.1 interface, need to use DC 24V 1A power adapter to power it (need to be prepared by the user) Parameters: Voltage: .7V Internal resistance: 56R, 220R 1K 20K adjustable Frequency: 40Hz, 350Hz, 2kHz, 14Hz adjustable Colour:Black Material:Plastic Package Contents: 1 * Tester 1Pair * Test leads 1Pair * Test clips Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.