UV glow- plus purple with silver & purple glitter (glows dark blue).
Blocks measure 3" x 2 1/2" x 1/8" (approx).
UV glow= 15+ minutes (Orange) to 12+ hours (green) as manufacturer states. After testing these out, the aqua seems to have the most steady glow, green does burn the longest and although dark blue lasts long, it's sometimes hard to tell because it's dark.
It is recommended to use a UV light on all glow products to speed up and extend glow process.