A must have item for building your coils for your MOD atomizers. It is accurate to 0.01 ohms. It is a compact (L) 70 mm (W) 45 mm (H) 19 mm and weighs 46 g and is made out of PC, Copper, PCB. The unit includes two 1.5v aaa dry batteries and a connector ring for various atomizer sizes. The device is easy to use by pushing a button to turn the tester on, screwing in the atomizer and the digital readout will display the ohms so you can safely create huge vapor clouds without over powering your battery.