I really like this fill light. There are 10 brightness settings. I generally find the lowest two to be good enough for fill light duty. Unfortunately the light is fussy about USB power sources. For example, with my Xiaomi 5000mAh battery pack there is visible PWM flickering on all tint modes at the lowest two brightness settings. On the lowest modes it is cured by plugging the ring light into a USB hub (not an externally powered one), and then into the power bank. This doesn't solve the flickering at setting 5/6 on neutral white. It's fine with laptop USB and the USB cable is quite long at 195cm (including in-line control, excluding USB plug). The diffusing ring does not look so easy to remove without damaging it, probably press fit, so I hesitate about repairability and modification.

I've always wanted something like this for projects. It is a little expensive for what it does, however. Although it arrived with ten mp3 files it seems to only be able to play one track. There is no loop or random play, the latter of which would be nice for a DIY panic/BS button toy. As far as sound files, it doesn't seem to recognise stereo mp3 files so you'll have to convert to mono. In my limited testing both 44.1 KHz and 48 KHz worked at 128 kbps. With no sound files the module emitted a police siren sound when triggered. 7.1 MB usable storage space. Write speed is a little slow, a few minutes to transfer a 4 MB song. Depending on source material it can be quite loud. Comes fitted with 100 mAh rechargeable li-ion cell. There is no indicator to reflect stage of charge.

Bought four of these in early 2017 for a kitchen light I use daily. All were on the cooler end of "3500K", approaching NW. Three are still going strong but one failed; I suspect the driver. I ordered two replacements; both are noticeably warmer. Simple fix, little soldering to use driver from new bulb. I added isolation slot to each PCB with a hacksaw for peace of mind.