The Pit Boss digital gauge is very well built and I have tested its accuracy with a professional lab quality gauge connected to a two position manifold so that both gauges can be done at the same time Connect to the tire at the same time, and at 30psi the pit boss was done. When tested at 35psi it showed 35.1psi and at 40psi the Pit Boss showed exactly 40psi. I can't imagine anyone needing more precision.