When only a serious “monster truck” style knobby off-road tire will do the PRIMO Knobby is for you! Just pump to 65 psi and you’re all set to go! Perfect for camping and/or any other off-road excursions! **IMPORTANT: Intended for a custom 24″ (507) wheel not a standard wheelchair size 24″ (540). Features: Price per Tire (1) Non-Marking Size: 24″ x 1.95″ (50-507) *Fits (507) Wheels not standard wheelchair size (540). Color: Grey Tread / Black Sidewall 65 psi