Fangrui Product Details 1. High Safety: Asa Test Does Not Require The Circuit Board To Be Powered On; Asa Test Does Not Involve Circuit Principles And Does Not Require The Circuit To Be In Working State 2. Strong Adaptability: Asa Test Does Not Involve The Function 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. Voltage: 4v;internal Resistance: 50r, 500r, 1k, 2k, 3k, 4k, 5k, 6k, 7k Adjustable;frequency: 20hz, 100hz, 500hz, 1khz, 2khz, 3khz, 4khz, 5khz, 6khz, 7khz, 8khz, 9khz, 10khz, 11khz, 12khz, 13khz, 14khz, 15khz Adjustable;size: 140x80x40;weight: 270g For Main Unit Features: 1. Support Dual-channel Signal Input 2. Support 18 Adjustable Frequency Levels, 9 Adjustable Internal Resistance Levels 3. Adjustable B Channel Position 4. Support A Channel Or A+b Channel Display 5. Support Trigger Signal Output (5v) 6. Built-in 3000mah Lithium Battery, Charged Using Type-c Interface 7. 2.0 Inch Tft Col