Because my friend accidentally bought 100 of these instead of 10. It lights up in various different colours. The bulb is about the size of my thumb. It's not a regular sized bulb, if you were thinking that. Good for clubbing at night time or just being out at night. She gave me one for free and she's like "only if you wear it and blog and tweet about it!" Apparently these were everywhere like last year. I don't remember seeing them EVER. XD
She has a stall at Glebe Markets on Saturdays. She sells necklaces, pendants, earrings and bracelets. It's near the female toilets if you want to drop by!