I purchased the last two ORIGINAL Glow Ball sets for my Sega Viper Night Drivin Pinball machine 5 yrs ago (apx $1200 a set) and was lucky to get them from a X Sega employee from the USA.
These are the original glow balls which last forever and are the correct pinball weight for a glow all ( not same weight as std silver ball).
People have never been able to successfully copy them since 1999 originals.
Rare as rocking horse shit and in high demand for original sets.