It wasn’t clear if it comes with a chip, but it sounded from reviews like the chips frequently fall out and get lost so removal should be easy to put in a superior chip of my choice (like the multi-technology implant capsule chips) which could be affixed in with silicone or similar so it doesn’t fall out.
I presume it would come with a cheap non-modifiable EM type chip or similar if it comes with anything. My objective is to be able to add “clone a hotel or similar key to something I already wear” so I am guessing Mifaire Classis MAGIC chip and T5577 would be the most common 2 to want.
Goal is to have a body worn replacement for hotel keys and similar so I could open my room door more easily with full hands, or if I don’t have pockets for a keycard (e.g. wearing a costume, swimsuit, etc). I often wear a watch, so that was the logical first thing to wish I could add it to.