These Letterbox Boxes measure 165mm x 120mm x 20mm and are perfect for efficiently shipping small, lightweight items — including mobile phones. Their slightly larger dimensions make them ideal for securely packaging smartphones, fabric swatches, and other similar-sized items, offering both protection and a snug fit. Engineered for quick and easy assembly, you can secure your items within seconds using the two peel-and-seal strips at both ends, eliminating the need for packing tape. These boxes are designed to fit within Royal Mail’s Large Letter size, helping to reduce postage costs. Delivered flat-packed in bundles of 60 for easy storage, they are 100% plastic-free, fully recyclable, and biodegradable, making them an excellent planet-friendly choice.