Coronado CEMAX eyepieces and barlows are not filters and for Solar observing must be used in conjunction with a Coronado Ha Solar telescope.
Coronado CEMAX 18mm Eyepiece (1.25") - for use with Coronado H-alpha Solar Telescopes and filters. 1.25" Barrel Size. Specifically designed for use at H-alpha (or Ha) wavelengths, this specialty eyepiece uses optimised coatings to enhance contrast, minimize glare and also affords excellent contrast for planetary viewing. Includes caps.
Features 20mm eye relief, 52° field of view, and rubber eye guard.