Brompton Front Axle Nylon Hook for Mudguard Stay front wheel

This Nylon hook is used on left side (with mudguard) and right side (with mudguard and rack) on Brompton folding bikes.

When your Brompton bike is folded, this hook hooks the front fork to the rear frame to stop it unfolding when you pick it up. (in combination with the seatpost being in the down position).

One of the "essential" Brompton spare parts - without this your Brompton won't stay folded properly.