Bottom Bracket Tool - BBT-9 - from Park Tool USA

Park Tool BBT-9 16 notch bottom bracket tool

One end of the BBT-9 securely engages the 16 notches of the bottom bracket cups, while the other end engages the 8 internal splines of the crank arm adjustment cap. Also fits the Campagnolo Ultra-Torque bottom bracket cups.Weight: 280g (10oz)

The BBT-9 works with many external bearing crank set bottom brackets including:

If you want to use a torque wrench to get correct tightness, then an alternative is the BBT-19 bottom bracket tool.

Park Tool Ref: BBT-9