Electronics Nite Ize Radiant 50 Bike Lights. The Radiant 50 bike light is available in red and can be set to steady day or day safe mode. It has a curved rubber back and comes with two sets of restraint straps so it can be mounted horizontally or vertically in a variety of places on a bike. It is an ideal rear indicator light for cyclists to be seen and safe, day or night. 15 lumens. Dimensions: 40mm x 68mm x 38mm. Weight: 64gr.