GPS bike computers, wireless power meters, cell phones (camera, music, weather alerts, and texting your whereabouts to your SO, and in one tiny form factor), wireless earbuds, USB rechargeable bar and tail LED lights, and small portable USB battery packs and 3 different USB cord types (mini, micro, and USB-C) to recharge it all on the 6+ hour long distance stuff.
So...technically nothing to do with the "bike" at all, but I wouldn't/couldn't ride without it all. How did cyclists get along without all this stuff 15+ years ago, those were very dark times indeed (both literally and figuratively).
Last edited by Riveting; 12-11-20 at 10:52 AM.