Models are specified based on wavelength ranges for different applications. The following graph shows available models for  standard configurations. In addition, Model 500  simply covers a range of both Model 100 and 400. Customized products  are available with wavelength range extension further down to DUV or Infrared (IR) ranges. Normally:

    Model 100 covers a wavelength range from DUV to NIR range up to 1100nm.

    Model 200 covers DUV and Visible range.

    Model 300 covers Visible range, starting from 370nm to 850nm

    Model 400 covers NIR range starting from 900nm typically

    Model 450 covers Vis to NIR range, starting from 370nm up to 1700nm typically

    Model 500 covers DUV to NIR range, up to 2500nm

    Model 600 covers NIR to IR range (1.7um to 17um or 1.7um to 30um)

Wavelength range coverage depends on several factors such as light source, detectors, optics used in system, light delivery method (using fibers or not). Because of these factors, all tools can be customized based on specific application. For example, NIR range can be covered up to 1700nm or 2200nm or 2500nm etc. DUV range can be down to 190 nm.