Features: 1) Design patent 2) semiconductor sensor inside 3) warm-up time:within 10 seconds 4) response time :within 5 seconds 5) Operation temperature:5-40 oC 6) Convenient to carry by keychain 7) Countdown and count-up timer keeps the deadline of your parking 8) 3 test steps with LED indication 9) test result: Safety: under 0.02% BAC Caution: 0.02% - 0.05% BAC Danger: over 0.05% BAC 10) Battery: 2 x AAA alkaline batteries (not included) 11) Clock: uses 1 x AG13 battery (included) 12) Size: 76 x 35 x 22mm 13) print size: 12 x 15 mmoC