Silvacore Pro by Duraflue Nu-lead lead roof flashing 0-45 degree FOR ALL DIAMETERS OF PIPEIt is for all diameters of twin wall clip together chimney pipe as you cut the rubber bit following a designated line with sharp scissors. Use when you have a slate roof and desire higher quality than the aluminium version. For tiles and slate roofs, lead is best. This is a twin wall clip together chimney part used to build a new chimney. Twin wall clip together chimney can be as close as 5cm to combustible materials (7cm if passing through a sealed