Features: HT2302 accurately measures earth resistance and voltage, very suitable for electric system, industrial equipment, etc. This tester provides two methods for the earth resistance measurement: bi-poles and -poles, very convenient. LCD backlit display, easy for data reading, ensures users can get the measurements even in low light condition. Up to 100 groups of data can be stored, which will not be lost even in case of power down, inquired for better analysis. It is capable to offer maximum, minimum or average value, relative measurement mode; auto shutdown is for energy-saving. Specifications: Material: ABS Color: Black & Red Power Supply: 8 x 1.5V AA Battery (Not included) Measurement Methods: 1. The earth resistance is measured by the constant current conversion . This uses the test current with about 800Hz frequency and about 3MA. 2. The measurement of the earth voltage adopts average numerical rectification . Working Condition: 0~40, Relative Humidity 85% Storage Condition: -10~50, Relative Humidity 85% Item Size: About 18.6 x 14 x 6.8cm / 7.48 x 5.51 x 2.75in Package Contents: 1 x Earth Resistance Tester 1 x Red Test Wire (15m) 1 x Green Test Wire (10m) 1 x Black Test Wire (5m) 2 x Auxiliary Earth Bar 1 x Carrying Bag 1 x English manual 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.