General description Royal Mail Large Letter PIP Cardboard Postal Boxes are high-quality, UK-manufactured corrugated boxes designed specifically for the Royal Mail 'large letter' postal system. These brown and white single wall die cut boxes are easy to assemble, featuring fold-over ends and "earlock" lids, making them ideal for secure packaging. Technical specifications Box style: C4 Internal dimensions: 332 x 245 x 22 mm External dimensions: 332 x 245 x 24 mm Max size allowed by Royal Mail as a "large letter"
