The Fieldpiece ACH4 current clamp is a small size accessory head for quickly reading up to 400 AC amps. The Fieldpiece ACH4's claw feature at the top of the clamp allows for quickly picking out the wire you need to measure and isolating it in the clamp. Once the current carrying conductor is isolated, the amperage is converted to mVAC for reading directly on the meter. The Fieldpiece ACH4 works with the Fieldpiece €œStick meter, EHDL1 Electronic Handle, DL3 Data Logger, the HG2 HVAC Guide System Analyzer or any other digital multimeter (with mVAC range) connected by Fieldpiece ADLS2 detachable silicone leads or AHDL1 handle adapter.