I just took mine apart. It’s an Omten switch, but not the usual white one I see. It’s black, 12x17x10mm It’s got a “3” on the plunger, and an “A” on the body. It also says “PBS-101C” on the switch body itself. The 101C-400 is a switch model that matches dimensionally and is rated 30V 1A, but the markings don’t match up 100%. It certainly feels different than any of the other Omten switches I’ve used, with very little mush at the beginning of travel and a very crisp actuation.