below referring to fig9 the knob comprises a plurality of locating elements configured to cooperate with the lens 35 and diffuser 40 specifically the underside of the enlarged head 67 comprises a pair of elongated ridges or ribs 70 that extend along the lobes 68 the ridges 70 are configured to mate with the recesses 37 formed around the opening in the lens 35 specifically the ridges 70 are configured so that the ridges can be aligned with and seated in the notches 37 in the lens in this way the cooperating ridges and recesses will impede movement of the actuator 60 relative to the lens the knob 62 also includes locating tabs 71 formed on the stem 64 the locating tabs are configured to mate with the locating notches 47 formed in the central aperture of the diffuser 40 in this way the locating tabs 71 key into the diffuser notches 47 the cooperating locating tabs 71 and notches 47 impede rotational movement of the actuator relative to the diffuser 40 the rotatable knob 62 houses the dimmer actuator 75 that is actuable to dim the light level for the leds in the light the dimmer actuator 75 comprises an elongated stem 78 and an enlarged head 76 the stem 78 is configured to slide within the central bore 65 of the knob 62 specifically in the present instance the dimmer actuator is inserted into the bore 65 of the actuator knob so that the stem of the dimmer actuator is coaxial with the stem 64 of the knob a biasing element such as a coil spring.