At the start of nearly every trail ride, you air down the tires, which requires two tools. One is a good air pressure gauge that accurately reads pressure under 20 psi. This one is from Power Tank and is liquid filled for extreme accuracy and has rubber insulation around the gauge to protect it. You’ll also need a tool to quickly deflate the tires. We like this deflator from Rugged Ridge because you can thread individual pieces onto all four tires at once and check the pressure while the tires are deflating. Currie Enterprises offers an EZ Tire Deflator which is a combo gauge and deflation tool that is quick and easy to use.