4003 Treble Bezel Cove in Smooth Chrome. Cove has a recessed pocket for thumb anchoring.

4003 series have a stepped down center to follow the contours of the stepped down center of the factory chrome surround. These will fit into earlier 4001 straight across surrounds, but an 4001 Specific Treble Bezel will look nicer in a 4001 straight surround.