"This is a fantastic little VV tube, it measures Ohms, Battery Voltage,Vaping voltage and a special little thing I love is wattage, (hold positive and negative for a few seconds) it will ensure that as the battery level drops your vaping experience remains constant. Solid, Heavy, and shiny... Just make sure you buy some batteries and a charger with it (I have some 18650's) I recently had a lavatube (looks like this one) twice the price half of the features and solidity... 5 stars from me One con is that if the top of your battery is crushed, you may need to bend it up to reach the positive tine inside the device...no biggie, otherwise get new batteries :)"