Ted Striker
Foot's on the other hand
Absurd and pricey.....IMO i'd say it adds £1500 to the shop price of most bikes!
It's not the week (for me) to argue the case for it(!), though I think it's awesome. It's added £300ish to 2 of my builds with it though I'd never look back. I've got cabled bikes (modern/indexed, old/friction and mtb) though I'm always mucking them up. I entirely appreciate with a rudimentary level of bike mechanic knowledge I wouldn't have the problems I do, but (battery aside) one-less-thing-to-worry-about matters a lot to me.