I've bought three of these for around the house ..
https://www.ebay.co.uk/itm/285784010288.. so if i ever need more than one I can borrow one from another room.
Powered from 5v USB power supply. I'm guessing it can be powered from a power bank too but I've never needed to do that.
Inside it has one strip of warm white, one strip of cold white, and the third setting is both on at the same time. Then there's a setting to control the brightness.
It's possibly a little too dim but I just swing the arm closer to what I'm looking at.
I've also used it to inspect the tip of a turntable stylus by taping a usb microscope onto the light (to provide good ambient lighting).
It's not the best of lights but is workable. I like the fact the power supply is separate as it gives options if a part fails.