2.5 tog grobag for 18-36 months. At the moment (for today only I think) they are £5 off and 3 for 2 on Tesco Direct. £13.33 each, great if you've got kids around the same age or for family, friends. You could also find two other friends who wanted a grobag for their little one and split the order.
100% Cotton outer, Polyester filling