Designed to snap on top of this 7/8"/22mm bolt-on-handlebar button ($11): https://www.amazon.com/dp/B07GPG41F4/
Uses one heavy duty SPDT ON-OFF-ON toggle, sideways, for blinkers ($10/3qty): https://www.amazon.com/dp/B07LBMM8JX/
Uses three "KCD1" 12V 1A style rocker switches for accessories ($6/8qty): https://www.amazon.com/dp/B0CVTRKJTV/

Left two switch boxes, are intended to toggle: daytime running lights, and street light bars.
Separate switch box, prints on side, superglues to left side, intended to toggle 5v USB voltage convertor.
Angled overhangs, over solder tabs, make this reasonably water-resistant, when riding through the rain. Created 2022.