The 30 mm 100-Degree Argon Purged Waterproof Eyepiece - 3" by Explore Scientific:

The 100-degree Explore Scientific eyepieces feature precision ground and assembled, fully multi-coated optical glass. Using a combination of Dense Crown, Light Crown, Dense Flint, and Lanthanum glass allows Explore to provide the best fusion of sharpness, contrast and color. Quality coatings are also highly durable and element edges are fully blackened to minimize any unnecessary dispersion of light. If you've never experienced a hyper-wide eyepiece, the 100-degrees of view are a treat, allowing your eye to relax and take in more detail than ever before. Plus, it is easier to find objects within the eyepiece view as well when compared to narrower fields of view. See large objects in their entirety! If you're observing with a manually operated telescope, especially a Dobsonian, you'll enjoy watching the object slowly drift through the field of view having to make only infrequent adjustments to the mount giving you more time to take in the view.

You probably won't be taking your eyepiece for a swim any time soon, and while you can easily clean your Explore Scientific waterproof eyepiece with a quick dunk, if the worst should happen, by purging the eyepiece housing with Argon and using waterproof seals, your eyepiece is also highly protected against the elements. Whether that be an unexpected rainstorm or just a dewy night, your Explore Scientific eyepiece will also not gather moisture while being stored which keeps those pristine optics in beautiful condition year after year. You can also quickly clean the optics without worry that the cleaning fluid will seep into the top of the eyepiece.

First there were .965" and 1.25" eyepieces, and then 2". Enter the next wave in barrel sizing: the 3" eyepiece! As its predecessor, a 3" barrel provides an even more eye-opening visual experience. Giant in all proportions, by virtue of the extra wide barrel the Explore Scientific 30 mm 3" eyepiece allows for a very large field stop. A larger field stop allows exponentially more light through. This dramatic 52.2 mm field stop brings out even more detail than you've ever seen before and brings faint object features to light.

OPT Product Number: ES-EPWP10030-01

AFOV: 100-Degrees
Focal Length: 30 mm
Eye Relief: 19 mm
Field Stop: 52.2 mm

3" Explore Scientific 30 mm 100-Degree Argon Purged Waterproof Eyepiece
Eye Guard

3" Eyepiece

Explore Scientific 30mm 100 Degree Argon Purged Waterproof Eyepiece - 3"