without one of these, a decent tyre pressure guage One of the presents i had for my birthday the other week. Nice and weighty and love the fact it measure's 1/10ths of psi too. Very important to keep them tyre's at the correct pressure for safety and economical reasons. You can programme this the settings you want for front and rear. Set it to read psi, bar or kpa and as a built in led torch too.