XT Racing "Mini-Lap" infrared receiver, model ML-101. In great shape and fully functional. Stores up to 40 laps in a session, measuring to a tenth of a second. Very compact, self contained receiver, no wires or additional components required. Sensors are on either side of the unit so it can be used with a beacon placed on the right or left of your track or circuit. Has two slots from top to bottom that can accept zip-ties to secure it, or you can add Velcro to the bottom to attach it to a flat surface. Uses a CR2032 battery and currently has a new one installed.