Lumien NEW Under Cabinet Lighting 1 Panel Kit - 20 inches, Anti-glare Edge-lit technology, Aluminum housing, 500 Lumens, 3000K Warm white, Dimmable On/off switch, UL listed power supply. CRI: 90.

Not really a warm white, but useful for inside cabinets because of their slim profile. I'm having to use a straw colored theatrical lighting gel taped over the light-source to get it a more natural colored light. Not ideal for my purposes, but does what it needs to do with a bit of help. If you're okay with a more typical LED white light, then this is a good fixture for some purposes so far. I wouldn't think it would be particularly good under a cabinet in a kitchen because it's not that bright - again, it would depend on your preferences.

Fit in a very tight spot under a kitchen cabinet. Adjustable light levels is also nice.