The Halo Backlit LED Downlight (BLD) incorporates state of the art lighting technology to create an ultra-low profile surface mounting luminaire with the performance and look of a traditional downlight. BLD4 is designed for installation in many 3-1/2 and 4 in. round or octagon junction boxes including pancake boxes. It can also retrofit in 4 in. aperture IC and Non-IC recessed housings.