1. No pump accuracy, 35lbs on the pump, 38lbs on the other two gauges including information on the car dashboard. 2. The device information screen was very small and not very bright even though the device was fully charged. It's also difficult to read without a magnifying glass. 3. It was not easy to use, taking a long time to carry only 2 pounds. tire pressure. I had to stay in place for almost 5 minutes. Eventually he actually started deflating the tire instead of increasing it. However, this could be user error. Overall very disappointing to say the least.