[Sunred]

So this was a thought that popped in my head. What non-belt type device could you see be the go-to henshin device for Kamen Rider in an alternate history? So picture an alternate timeline where Kamen Rider Ichigo and Nigo never used the belt as a henshin device and the rest of the riders after them did the same using this type of device as the go-to device.
Personally, I was thinking two things. First would be a motorcycle helmet or face mask where the rider would put it on and suits up so pretty much Riderman. Second one that I could think of is a pendant device that is disguised as a stopwatch.