For much of 2017, your choice as an Amazon shopper might have been 4" GetInLight .
An eternal hallway night light:
This 4" GetInLight draws 9 watts to produce 550 lumens, double the downward illumination from a 60 watt incandescent dimbulb. Adjusted to equal illumination, the bug-proofed GetInLight draws 4.5 watts, a reduction of more than 90%. That is nearly the full savings that is achievable with LED lighting, easily available now. This will shine on for at least thirty years with no need of maintenance, if AC Driver On Board lights are as durable as external converters of DC LEDs. Here over a guest bedroom door as a night light, the achievement is safety. There was no light here before.
On a bug-proofed RACO 175 junction box, 4" GetInLight draws up to gasketed sealing, via an awkward adapter ring. GetInLight has been a worthwhile nuisance, for lack of the adapter plate now included with a nearly identical 4" Westgate LED. Exactly identical boxes are the clearest indication GetInLight and Westgate are made in the same China factory. Amazon is the actual importer. Westgate and InLightMotion don't manufacture anything.
As an Amazon shopper in December 2017, you will find the Westgate now reviewed here, a better light and a better deal than the slimmer, more sleek GetInLight still offered at Amazon:
Westgate 9W 4" Dimmable Disk LED Surface Mount Disc Downlight Kit Accessories Included - Spun Aluminum Housing - Energy Star Rated - 550-600 Lumens 120V (1, 3000K Soft White)
Your cost: about $14. Go for it. With the Seoul Semiconductor Driver On Board, it will readily mount to any ceiling junction box, however overloaded with wiring and however unsafe from overheating of wires by those 100 watt or bigger bulbs you can't buy anymore. You want more light. You want safety. You want to do your part saving energy and money.
Here see the important box adapter plate that Amazon fails to ship, with GetInLight. See the very many paths that glow brightly within a can light or junction box, impossible of sealing. A bug entering the junction box will certainly die upon the luminaire lens, seeking and never finding, the heaven of diode contact. This is my typical installation on a sealed-bug-proof RACO 175 steel junction box. The deep RACO 175 boxes have been necessary for LED disk downlights with a bulky external driver from house AC power. See that even with the adaptable and rugged RACO 175, caulking is needed to keep bugs out.
Please find my positive review of this light as a Google Photos Album . Know right away that you must do better than the simple adoption suggested so far. Wiring with decrepit electrical insulation must be replaced. If your junction box is old and leaky or if you stuff this into a 4" can light, you will be happy, for awhile. Then you will see the lens darken from litter of dead bugs. LED lights do attract bugs, especially where seen from the ceiling interior as bright points, the stars that denote vertical wrongly and then madden.
Get used to LED disk downlighting. It doesn't look like your bulb, but it lasts forever, and saves more than 90% in operating cost versus point-source incandescent. Few of us have tried these, but they are our illumination of the future. We quickly see them as beautiful, and that will be especially true of the shapely little Westgate light
The Westgate-included adapter plate at the back side is released from the luminaire assembly and becomes part of the ceiling interface. Keyways in the luminaire are at 2 3/4" pitch, and the adapter plate reaches out to 3 1/2" pitch more-commonly found.
Now consider Westgate luminance (glare) numbers. Diode luminance and array luminance are both small compared to a glaring light like Nicor DLS4.
Assess brightness of the Westgate LED, comparative task illumination at my comparison stand. During evaluation of an EiKO LED edge-light, compare several LED luminaires stage left, against a 100 watt point-source incandescent bulb at stage right. The point source bulb is that still legally sold, Philips EcoVantage 1490 lumens, 72 watts. Choose LED luminaires of 3000° color temperature with large beam angle typically 120°.
4" Glimpse of 2013, called 450 lumens, at left. Philips EcoVantage "100 watt" bulb at right. I have made this comparison many times, always finding equal brightness and slight difference of color temperature with bulb nearer 2700°K. I call both "B4", by definition. This is the brightness by which very many homes with 8-foot ceilings have set luminaire spacing. B4, about 500 lumens, will be the goal in usual LED swaps for closets, narrow hallways and small bathrooms. In larger rooms with want of productive activity, we will want more than B4 in swaps upon existing junction boxes. More light is good.
The luminaire at left in this photo is Westgate 4". The Westgate is only a bit brighter. I have found in very many comparisons that a "100 watt" bulb gives task illumination comparable to a LED disk of about 500 lumens with about 120° beam angle. Question that the Westgate is 600 lumens.