The Spectronic 20+ Series of spectrophotometers are updated versions of the Spectronic 20 and the Spectronic 20D. Improved ease-of-use and performance makes these reliable instruments an exceptional value. New solid state detector covers the entire range of 340 nm to 950 nm. Changing filters requires a push of the lever. A single cable connects your computer or printer to the 20D+. Just push the print button on the front panel to send data to your printer. The sample compartment on both models holds a variety of adapters, cuvettes, and test tubes for running a diverse range of chemical tests. The Spectronic 20+ Series has a slit width of 20 nm. Wavelength range is 340 to 950 nm with accuracy of (0.5% T, respectively. Stray radiant energy is less than 0.5% T over entire wavelength range. Both models come with built-in filter selector, silicon detector, 1/2 sampling compartment, 1 box (12) 1/2 test tube cuvettes, operator's manual and dust cover. In addition, the model 20D+ has an RS-232C serial port. Three year warranty on parts and labor. 115V (other voltages available). Weight, 18 lbs.