Designed to prevent draughts through letterboxes. Warmseal products can help your customers reduce heat loss by up to 35%, saving on energy bills. Easy to fit and remove if necessary. Easily cut to size if needed. Draught-proofing around windows and doors could save you around £30 a year*. Savings based on a typical gas-fuelled semi-detached property in England, Scotland or Wales. (Energy Savings Trust)