* High quality transmission diffraction grating mounted in a custom low profile 1.25 inch filter cell
* Low profile (5.2mm above the thread) filter suitable for use in close coupled filter wheels
* Anti- reflection coated glass protects the grating surface
* High efficiency 200 lines/mm blazed design
* Spectrum direction marked on the filter cell
* Optimised for the larger aperture longer focal length telescope with larger camera sensors
* Star and spectrum can be recorded in the same image, which aids identification and calibration
*Can be used with filter wheels designed for unmounted filters using the optional mounting kit