The ThinKing by Russian watchmaker Konstantin Chaykin is only 1.65 mm thick, making it the world’s thinnest mechanical wristwatch.

The “arms race” for the world’s thinnest wristwatch has been in full swing for a few years now, with some of the most prestigious watch brands on Earth trying to one-up each other with ingenious designs. The latest to claim the coveted title is independent watchmaker Konstantin Chaykin with its ThinKing prototype, a 1.65-thick masterpiece that is so incredibly thin it needs a special wristband. The ThinKing’s case is so delicate that the simple pressure from being worn is enough to damage it, so the special strap made of alligator leather and elastic inserts with titanium has to absorb some of the shocks, twisting and bending.