A finned diecast lamphousing having an extended open
front, fitted with a lamp holder and a 12V 24W lamp. A
metal plate having a single slit and triple slits on either side
of the plate is white on one side and black on the reverse.
 
The metal strip in conjunction with a cylindrical biconvex
lens produces a variety of rays suitable for performing
various light experiments. 

(Supplied without lens).