A pneumatic tire with a tread has crown main grooves, shoulder main grooves, a pair of middle ribs between the crown main grooves and the shoulder main grooves, and a pair of shoulder ribs between the shoulder main groove and tread edge. A light source provides incident polarized light. The top printed circuit board and the intermediate printed circuit board are formed with communication holes for communicating the chambers with the outside. The tray has at least one drainage orifice adjacent the floor. The interface controller may be configured for coupling to a plurality of disk drives.