Baader CMOS UV/IR-Cut L (420 – 685 nm) Bandpass filter suitable for use on f/15 to f/1.8 telescopes
Planeoptically polished and hard coated! Blocks UV below 400nm and IR above (SII) 680nm. Maximum transmission, scratchproof hard coated.
This UV/IR cut filter blocks UV and IR rays to maintain the colour temperature you want, eliminating false colour fringes around bright stars.