No 11 Yellow-Green colour filter to fit 1.25" filter threads (78% transmission). Enhances the cloud belt details of Jupiter and Saturn. Improves contrast and darkens large surface details on Mars and may enhance visual detail on the discs of Uranus and Neptune (in larger aperture telescopes 9"+). The filter is made of top quality optical glass and is mounted in a black anodised aluminium holder and is supplied in plastic storage case.