Milton Roy Spectronic 5O1 Spectrophotometer, 115V, 2 Amps, model 33.51.03, is manufactured by Milton Roy Company. The Milton Roy Spectronic 501 is a digital, single-beam visible spectrophotometer with a wavelength range of 325nm to 999nm, +/-1nm. The 501 has a built-in RS-232 interface and is microprocessor controlled. This spectrophotometer has a spectral slitwidth < 5nm. The Spectronic 501 is easy to use - enter the wavelength setting and other test parameters through the keyboard. The 501 gives absorbance, concentration and % transmittance. Sample compartment size is 17.1cm D x 10.6cm W x 10.2cm H.