Apologies for somewhat of a re-post, I didn't think it appropriate to edit the old post as the deal has changed and is a single item this time. I’ve been informed that there’s now a code visible on Amazon for the SD05 that gives 25% off the price; this brings the price down from $54.99 to $41.25.
The SD05 is a diving/underwater light using a Cree XHP50.2 emitter that uses internal magnets to activate modes so as to keep the light sealed; the rotating ring has the magnet in it, and lifts the contact into place.
Some great pics of it in this BudgetLightForum review (note that one of the negatives, the three minute stepdown timer, has been removed).
Some videos of it in use as provided to me by Sofirn are here: