If you need a little bottle for dressing, sauce such as ketchup, mayo or soy sauce for a picnic or lunch box, these Sistema Sauce 'To Go' Bottles fit the bill perfectly!
They are BPA free which means that the plastic they are made of is thought to be safer for food containers than plastics which contain the BPA chemical.
I bought these from Waitrose for £2.49.
Asda online sell them too.
You get 3 little screw-top bottles in funky colours. They hold 35ml of liquid which makes it easy to put a propointed portion into the bottle.
They seem pretty robust and with a snap on lid are lovely and secure. They dispense the sauce easily too.