Whatever happened to nice mudguard-mounted reflectors (or to any nice reflectors, for that matter?) The new Grand Cru reflector really is lovely, a little jewel on the rear mudguard. The body is CNC cut from an aluminum billet and polished to a near-mirror finish.
Notice how the back is scalloped to fit the fender. It's held on with a single screw. Diameter is 42mm.