The Time-O-Lite M-72R Darkroom Timer is the same design as the Time-O-Lite GR90 except for the addition of a second outlet for control of the safelight.
When the start button is pushed, it will turn the safelight off, and turn it on upon completion of the exposure cycle. It also incorporates the same synchronous motor coupled with automatic reset.
A toggle switch controls power to the enlarger permitting either timed or constant output(for focusing). The timer incorporates a maximum 60 second cycle, has a luminous dial, chemically resistant Lexan case, and can be either wall or table mounted.
A polarized 2-wire grounded plug and recepticles as well as a 750 load capacity make the M-72R a good choice for the everyday darkroom.