An illumination device that includes an elongated light pipe and attachment wings integrally formed on the sides of the light pipe so that the illumination device can be easily, yet securely, installed within a containment channel, such as those found on the underside of a vehicle step rail. The elongated light pipe is made of an optically transmissive material, the attachment wings are made of a different resilient material, and the overall device is a single extruded component that has a co-extrusion boundary separating the two materials. The illumination device illuminates the ground, for example, when passengers are entering or exiting the vehicle.