Check the listing for details. NEW Replacement Knob Federal Signal Whelen Code 3 Slide Switch CenCom SoundOff. Condition: New. Listed at 9.99 USD. 1 Aftermarket Aluminum replacement slide switch knob for Federal Signal, Whelen, SoundOff , Code 3 and more! The knob has a set screw so it will not go missing! **IF YOU ARE NOT SURE IF IT FITS YOUR UNIT, SEND ME A MESSAGE!**This for a replacement knob only. Fits slim style shaft, slide switch. These will not fit the Unitrol Series units (Touchmaster/Delta or the smaller 183K) Some Examples of what it will fit:Federal Signal-SS2000 Series-Signal Master Controllers (Old and Newer Models)-SW400 Switch Box-Pathfinder Series-PA640 Whelen-CenCom Gold Controllers (Not the Newer style with the plastic knob that is one piece)-WeCan 6 Button Controller Code 3 -RLS-Rocker Series Switch Boxes-Most Slide Switches! SoundOff -Nergy Fenix-4200-Fenix One Z8536C1041AZ85361185A