280 x 400mm size sheet Techni Ice Sheets are resuable and will stay frozen longer than usual ice blocks and do not leak water when thawing. Techni Ice Sheets need to be frozen for at least 24 hours for best results. If sheets have thawed slightly, re-hydrate by immersing in water, dry thoroughly and freeze. Designed to go inside a cooler bag to keep your milk cold at the doorstep. We recommend one sheet per bottle of milk. Please Note: Refrigerated Items left out in cooler bag with Envirofreeze Ice Sheets is at the CUSTOMERS RISK. Please read our Terms and Conditions