Explore Scientific 52° Series 4.5mm Waterproof Eyepiece

The Explore Scientific 52° Series 4.5mm Waterproof Eyepiece is a flat-field, multi-element ocular with a 52-degree apparent field of view. It's a high-power eyepiece, the kind used for close observation of planets, double stars, and bright compact deep-sky objects, producing some of the highest magnification most amateur astronomers will use.

• Focal Length: 4.5mm focal length, built as a flat-field eyepiece with a 52° apparent field of view.
• Optical Design: 6 elements in 3 groups, edge blackened, with EMD (Enhanced Multi-Layer Deposition) coating on all lens-to-air surfaces.
• Barrel & Filter Thread: 1.25" O.D. / Double Taper barrel; accepts 1.125" x 42 TPI (fits standard 1.25" filters) filters.
• Eye Relief & Field Stop: 15mm of eye relief with a 4.1mm field stop diameter, and a removable flip-down soft silicone eyecup.
• Waterproofing: O-ring sealed and Argon gas purged, tested submerged under 1 meter of water for 30 minutes.
• Size & Weight: Measures 83.5mm, weighs 181.4 grams (6.4 oz).