All In Bike Multitool
The All In Bike Multitool is built for cyclists, but it won’t take up any space in your bike bag. Nor can you forget it at home because it slips into the [otherwise completely useless] hollow space in your bike’s crankshaft (that is, in the axle between the pedals), locking in place thanks to seven powerful neodymium magnets. If you need a hand, yank it out; the Italian-made tool comes equipped with four Allen keys, a T25 torx, and a Phillips bit — though you can swap out any of these with any standard bit. It’s also got a few slots for extra chain links but doesn’t come with a chain breaker tool, so pack one of those alongside a spare tube and tire levers.
Learn more at All In Multitool – roughly $70