... Features:1.This product is a alcohol tester designed for iPhone, it's small, exquisite and delicate design ... It powered by iPhone, just connect it to iPhone for use. 6. No need to use blowpipe, just ... then unlock Iphone, then press switch of tester for 2-3 seconds, at the same time LCD screen ... seconds, please blow to air hole and exhale into sensor for 3 to 5 seconds , after finishing Countdown ,display ...