This bracket allows rack mounted rear bicycles lights, both those intended for dynamo and battery operation, to be mounted on the seat post of a bicycle which does not have a rack. Both 50 mm and 80 mm hole spacings are provided, allowing for all normal rack mounted bicycle lights to be fitted on the seat-post. The bracket is unusual in that it requires only one metal bolt. This bolt both compresses the bracket against the seat post and holds the three printed parts of the bracket together. The angle of the light should be adjusted before the bolt is tightened. The bracket is designed to fit one inch (25.4 mm) seat posts.