This is a handle bar bracket for the Nxt head lights.

The Nxt can be mounted in 2 ways. It comes with a newly designed bracket
that fits all standard front forks. This bracket can be replaced by a
one-arm aluminum handlebar bracket. This allows the headlight to be
attached to the
handlebar.

This bracket has a diameter of 35,0 mm.

Technical description
Fits all Nxt head lights
Diameter ø 35,0 mm