ROYAL MAIL PIP LARGE LETTER MAIL CARDBOARD POSTAL BOXES C4 C5 C6 C7 Pack of 100
C4 325 x 225 x 20mm - 25 Boxes. C6 163 x 112 x 20mm - 25 Boxes. C5 229 x 159 x 20mm - 25 Boxes. 💡Why Choose Our Large Letter PiP Boxes?. Large Letter PiP Box. Save money. Cardboard Envelopes. Mini 101 x 101 x 20mm - 25 Boxes.