GSO 1.25″ Plossl Eyepiece – 4mm

The GSO Super-Plossls are available in a 1.25″ barrel size and 9 different focal lengths ranging from 4mm to 40mm. The 4mm, 6mm and 9mm models are great for high power planetary and lunar observation.  The 12mm and 15mm are perfect intermediate focal lengths, performing well on both deep-sky and planetary subjects.  The 20mm and 25mm models would be excellent choices for low power scanning of open star clusters and viewing larger galaxies. The 32mm and 40mm models offer a wide field and are superb for wide field scanning, detailed observations of large diffuse subjects or as a finder eyepiece. Features: – All eyepieces are fully multicoated (FMC) for maximum light transmission – High quality lenses provide the best-possible sharpness all over the field of view – Blackened lens edges reduce light scattering and improve contrast – Fold-down rubber eyecups to keep out stray light – Comfortable eye relief at all but the shortest focal lengths (As in all Plossl eyepieces, eye relief can get tight at the shorter focal lengths but this is design constraint, not a fault of these eyepieces) – Includes two end caps. Specifications Focal Length: 4mm Barrel Size: 1.25″ (31.7mm) Apparent Field of View (Mfg Specified): 52° Eye Relief (Designed): 6mm Filter Threads: Standard 1.25″ Filter Thread (M28.5 x 0.6) Coatings: Fully Multi-Coated Lens Elements: 4 Blackened Lens Edges: Yes Barrel Type: Smooth sided Optical Design: Plossl Height (With Eyeguard Extended): 52mm End Caps: 2 Rubber Eye Guard: Yes Weight: 80 gms