1.3 COLOR SELECTABLEPossibility of selecting color temperature for each track light by adjusting the slider on the back of the spot light. The three color modes are 3000k warm white, 4000k neutral white, and 5000K cool white 2.ONLY MATCH WITH J TYPE TRACKPls check the type of your track before it, these J type track lighting heads only compatible with Juno track lighting systems, and won't fit with H or L track(Track Rail not included in this package) 3.DIMMABLE & SUPER BRIGHT4 Pack 20W white track lighting, 36° beam angle, 2,000 Lumen real output for each(100w halogen equivalent), much brighter than others, and it can smoothly dim from 10% to with TRIAC dimmer 4.FLICKER-FREE, NO BUZZ, CRI 90+Combined with flicker- and showing the true color LED technology, the led track lights are great choice in multiple residential and commercial settings, especially for living room, kitchen, shop windows, art gallery, office...etc