The stunning large window box in Hampstead Lead is designed to fit terrace and bay windows exactly, providing a smart, chic finish to your home. Our beautiful clay fibre window boxes give your home a designer finish.They provide the most modern, smart and durable option which will stay looking amazing for many years. Recently featured in the Sunday Times and Stylist Magazine, they are an excellent way to enhance your property or make an excellent gift for house proud friends and family. not given Bay and Box products are made from clay fibre which is extremely durable and smart. They are fully weather-proof, so do not rust, scratch or discolour like Zinc or metal planters can. They come with a ready-made drainage hole.