I purchased this device after reading about it being DOT approved for Law Enforcement, coast guard certified and yaddiyaddiyadda. When I unpacked it and installed the batteries I notice that the pivot point for the battery cover is about a 1/32" plastic tab. The battery cover latch was no better. After installing the batteries and snapped the cover shut, they promptly ejected out the bottom of it... multiple times. This thing is made to the same standard as a carnival souvenir. In reading about the accuracy of the device in the manual provided it states "Accuracy at a Blood Alcohol Concentration greater than 0.032 has not been evaluated" The manual also states that a BAC level of 0.05% and over could impair your ability to drive. People are trusting this device to insure that their driving may not be impaired although the manual confirms that this device is not a safe method to test your BAC in those ranges.