LCD Digital Clamp Ground Resistance Meter Auto Power Off Clamp Earth Resistance Meter Tester for Weather Item Type: Clamp Ground Resistance Meter Model: ST4100 Battery: 1.5V AA Batteries x 4 (Shipped Without Batteries) Material: ABS Basic Parameters: Function: Grounding Resistance Test, Circuit Resistance Test Ambient Temperature And Humidity: 23℃±5 ℃, 75% Rh Below Measurement Mode: Mutual Inductance Mode Resistance Resolution: 0.001Ω Clamp Jaw Size: 55 x 32mm / 2.2 x 1.3in Clock Function: With Display Mode: 4 Digit LCD Display, Black Screen Design LCD Size: Approx. 46 x 36mm / 1.8 x 1.4in Measurement Time: 1 Time/Second Data Storage: 500 Groups, "MEM" Storage Indication, Flashing "MEM" Sign Indicates That The Storage Is Full. Data Access: "MR" Sign Indication When Accessing Data Overflow Display: "OL" Sign Indicates When The Overflow Is Over The Range Interference Test: Automatic Identification Of Interference Signal, "NOISE" Sign Indication When Interference Current Is Large Alarm Function: Alarm Prompt When The Measured Value Exceeds The Alarm Setting Value Battery Voltage: Realtime Display Of Battery Power Automatic Shutdown: Can Be Set To 5, 10, 15, 20 Minutes, OFF Several Ways, OFF Means Cancel Automatic Shutdown, The Default Is 5 Minutes.