The Pulsar Gigi is 2 inches tall with a big 500 mAh battery. It’s got a spring-loaded slot for your 510 battery with 3 VV settings (3.4V, 3.7V, 4.0V). Click it 5 times to turn on/off and 3 times to adjust the temperature. LED lights notify you for temp change and low battery. The coolest part though, is that its colour changing! It has a heat reactive finish, so will change colour from the heat in your hand.