General description Royal Mail Large Letter PIP Cardboard Postal Boxes are high-quality, single-wall die-cut boxes designed specifically for the Royal Mail 'large letter' postal system. Manufactured in the UK, these corrugated boxes are easy to assemble with 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 Maximum size allowed by Royal Mail for a "large letter"
