This stop light switch mounts near the brake pedal and closes the circuit that fires the stop lamps once the pedal is depressed, warning traffic behind. It measures 4.3 x 4.3 x 4.9 inches and ships as a single unit. It fits Mack, Navistar, Kenworth, and GMC Truck applications.Interchanges:16767301676730C1171548R911MR11711MR1428R1MR2328R1MR3352R226411241717024604042769634333-1676730C14333-505026C14333-873706R914333-892293R91505026505026C1745-226411745-275719745-275799745-276963801266873706873706R91892293892293R91K301-123RBE13250LST-3605FeaturesBrake light switch for stop lamp activationDimensions: 4.3 x 4.3 x 4.9 inchesSold as 1 EACHTech SpecsHeight: 4.3 inWidth: 4.3 inLength: 4.9 inUnit of Measure: EACH