They can be charged in direct sunlight or by UV light.
A regular house light doesn’t always give them the proper charge.
The longer they sit the longer they glow.
The ones that are white/color/glow have a sparkle on the metal. Skinny Tumbler 20oz
S P E C S:
-Keeps drinks hot or cold for up to 4 hours.
-Vacuum seal keeps liquids and carbonation fresh.
-Made from double-walled non-toxic stainless steel.
P R I N T I N G
- Digitally and professionally printed
- Design on Both Side of Tumbler
- Not Vinyl, Will not scratch or fade