Baader D-ERF Energy Rejection Filters for H-alpha Solar Observation Size:160mm operated by 2XAAA batteries (not

operated by 2XAAA batteries (not included)

High Speed – Rotates up to 7

compatibility with longer focal length eyepieces

1mm Centre Positive Socket

APS-C sensors require telescopes with an adequately corrected image circle

Baader D-ERF Energy Rejection Filters for H-alpha Solar Observation Size:160mm operated by 2XAAA batteries (notBaader Energy Rejection Filter (D ERF) H Alpha Solar Observation Filter The Baader Energy Rejection Filter (D ERF) is specifically designed for H alpha solar observation, allowing telescopes to achieve full aperture resolving power. This filter significantly reduces the thermal energy entering the telescope, protecting your solar spectrum filter and minimizing thermally induced seeing effects for a more stable and detailed observation experience.