Quantity: One Piece Pocket Digital Multimeter Auto-off, 3 1/2 digits LCD display, maximum reading 1999, more energy-saving. Auto-ranging, data hold, low battery indication, over-range indication, negative polarity indication. The Mini Digital DC Voltmeter is a very compact digital multimeter with all the necessary functions. DC/AC Voltage, AC/DC Amps, Ohms and Diodes, Continuity Tests with Tones. Powered by 2 x 1.5V button batteries, LR44 or equivalent, the insulating tape must be removed from the batteries before first use. (not included) High quality, foldable and portable design, small size, stable, accurate and reliable, easy to carry and use. Hint: 1. If the device cannot be turned on, please open the back cover to check the battery. (The package contents may not include batteries.) 2. Please do not use this device below 0 degrees Celsius! 3. If the continuity test does not sound, please remember to switch to the correct function. 1) Display: 3 1/2 digit LCD, the maximum reading is 1999 2) Over-range indication: Only the number "1" is displayed on the screen 3) Negative polarity indication: The negative sign "-" is displayed in 4) Sampling rate: about 2-3 times/second 5) Operating environment: temperature: 0-40 degrees 6) Storage temperature: Temperature: -10-50 degrees Good quality product