What is it? 18 Hour Ice Block Pack 2 x 440g (2 x 15.5 Oz) Why use it? Put these ice blocks in your cool box, lunch box and keeps your food and drinks cool for up to 18hours! The ideal cooling device for picnics, walks, work, travelling or anytime you are on the go! Place the Ice Blocks in the freezer till the liquid inside is completely solid before using. It is re-usable, must be cleaned only with warm water and a dry cloth to dry off. It is made of hard plastic. What is in the box? 2 x 440g 18 Hour Ice Block/Ice Pack