Drive Safe is using a electrochemical sensor in order to achieve a high precision reading in only five seconds. The device comes with a set of AA batteries for powering the device

Sensor: electrochemical
Detection: 0.000 to 0.400% BAC (blood alcohol content)
Accuracy (margin of error): ± 0.05 (0.10 %) *(See FAQ)
Display: 4 digits (0.000)
Dimensions: 5.9 cm x 14.0 cm x 2.6 cm
Included items: 5 mouthpieces and a carrying case
Suggested calibration: every 12 months or 1500 tests
Warming time: 5 to 10 seconds
Works with: 2 AA batteries (included)
Warranty: 12 months