Diving Masks are part of a much more comprehensive diving set, added during the Compound Update back in May of 2018.
While this eye covering offers no defensive statistics of any kind, they do boost your ability to see in an underwater environment, reducing the blur factor by a significant margin.
One hefty drawback is that while worn, they limit your scope of peripheral vision, similar to but not quite as bad as the Heavy Plate Helmet. This makes their use on land ill-advised.
Acquiring diving masks is relatively straight forward with them being acquired in quite a number of ways. In addition to being purchasable at any Fishing Village monument for 15 Scrap, they also spawn in several crate types and can be dropped by scientist NPCs.
While not common practice to recycle as most pairs simply end up as ground clutter, doing so will yield a small amount of Metal Fragments early in a wipe cycle.
As far as general appearance, they appear as you would expect them to – as a standard pool diving mask. They are currently not a skinnable item type.