This student optical bench Kit requires a Hodson Light Box as its light source. (not included - can be purchased separately). The 1.2m long straight alloy rail is complete with metric scale & carries all the kit parts on plastic mounts. Kit contains mount for lightbox, optical targets & scale, white screen, large prism & rotatable table, set of 50mm bi-convex & bi-concave glass lenses of various focal lengths with holders.