To get the most traction out of modern wide tyres and rims their pressure is incredibly important and 1psi makes a huge difference. Accu-Gages are CNC machined from brass and individually tested to ensure an accuracy which even the best floor-pumps can’t reach. The Accu-gauge will help you measure down to half-a-psi and measures to a maximum of 30psi. Fits presta valves and is small enough to stick in your hydration or hip pack.