They're basically ten kirby grips in one. You twist your hair up in a bun and to hold it in position you just need to place one of these at an angle, twisting around like a cockscrew as it locks the hair in place. One in each side (think of it like chopsticks) will do the job well, keeping hair in the perfect style and secure as long as you need. If you want a casual up do these little gadgets are fantastic - I've been wearing my hair in a bun for work and keeping it in all night becasue it's really comfy. You don't get the tight, tugging feeling you sometimes get with hair bands or buns, because it's actually really loose. For a quid you can't really go wrong!
Available from Primark - £1.00 for two.