Wide Field Binocular using cheap telephoto attachments

These wide field binoculars sit at a weird spot.
Due to their low magnification power, their exit pupil is way larger than what can be collected by the human eye.
E.g.: 58/2 = 29mm in this case, over 7 maybe 9mm of a young adult's eyes.
So while optically these glasses do not really makes sense, they nevertheless are fun to use, and there seems to be a market for them, since commercial products exist. They offer a wide field of view, since one can basically scan around inside the much larger exit pupil and thus also offer easy usability.

Here is a DIY version with two simple press fit adapters and an oversized screw for two cheap telephoto attachments. They offer no option to refocus the lens, nor do they have antireflective coating. Nevertheless one can spot some Messier objetcs that are hidden by the naked eye, and usuall a full celestial constellation fits into the field of view.
An eyecup model to be printed in TPU is included.
It will cover the backside threads and protect your eyeglasses from getting scratched by the metal housing.

I also included a model for a backside cover.
It works but the design is quite thin, compared to the front lens cover that comes with the teleadapter.

One could also design a custom lens housing with a simple focusing mechanism and reuse the lenses provided from these adapters.
Plus once you have them out you can blacken the edge of the lenses, reducing the effect of stray light.