40mm tournament grade.  They are super bright and great for nighttime ping pong and beer pong games.  The balls can be resued endless amount of times just a quick exposure to light and they are ready to glow.

Need continuous glow?  They react perfectly (always glowing)  when exposed to a black light.

These Balls are blue in color when not glowing, when glowing they will glow aqua.  Balls are packed in poly bags , non retail packaging .