Suitable to use outside in gardens as a decorative garden feature, to highlight plant pots or the edge of paths for example or to decorate vases in windows etc, the only limit is your imagination! These decorative aggregates are the bright eco friendly lighting choice that use no electricity or battery power. They absorb light throughout the day & then slowly release the light as an afterglow throughout the evening. The brightness of them are 10 times brighter than traditional Zinc Sulphide ' Glow in the Dark' products such as ' Glow Stars' used in kids bedrooms. Green glows the brightest, aqua glows the longest, but blue is the most popular! The 'glow' time really depends on a number of factors such as which colour you choose, how much light they get in the daytime, & how dark an area they are in (they look better the darker the surrounding area). Even down to how different people see 'glow' in the dark so there's no concrete answer, but 'afterglow' is around 10 hours. These pebbles will glow again & again for years & years. Try mixing pebbles & gravel together perhaps in different colours for a bespoke effect! Each 250g bag of glow pebbles contains Approx. 75 pebbles Find out more about how glow in the dark works to get the best out of your glow pebbles & gravel. For more information see our Getting Started with Glow Gravel & Pebbles PDF help sheet.