The V-660 has a user-friend features that include IQ accessory function for automatic accessory recognition and IQ start for immediate execution of registered control programs when conducting routine measurements. It also has an exceptional stray light rejection. A true double monochromator reduces stray light below 0.00008%. The high stray light rejection makes this instrument an excellent choice for the measurement of high optical density samples up to 6 absorbance units. The V-660 is a double-beam spectrophotometer utilizing a double monochromator and a photomultiplier tube detector. The use of a double monochromator provides high resolution with extremely low stray light (0.00008%) to assure more precise measurement over a wide photometric range. Extended photometric linearity up to 6 Abs enables measurement of highly absorbing samples and is also effective for filter measurements approaching 0 %T. Two graphical user interfaces are available including a newly redesigned intelligent remote module (iRM) with a color LCD touch screen and Spectra Manager™ II software, the latest version of JASCO's innovative cross-platform spectroscopy software. Both of these control and analysis interfaces allow full system control and advanced data processing. Spectra Manager CFR is a 21 CFR part 11 compliant version of software and is available as an option.