Design patent Semiconductor sensor inside; Warm-up time is within 10 seconds; Response time is within 5 seconds; Operation temperature:5-40; 3 test steps with LED indication Test result:- Green light: < 0.02% BAC; Yellow light: 0.02% ~ 0.05% BAC; Red light: ≥ 0.05% BAC; Battery: 2 x AAA alkaline batteries (included); Size: 85.2 x 39.2 x 20mm