PremierTeam pocket envelopes in size C5 (229 mm x 162 mm or 9 x 6 3/8) have a self seal opening flap on the short side and window to see the address. White C5 envelopes from PremierTeam measure 229 mm x 162 mm or 9 x 6 3/8 and are made from a quality 100gsm white paper to give you a professional look for every letter or mailing that you send. These envelopes are windowed to see the address, and feature interior security printing to protect the contents. The self seal flap has adhesive on both sides for a quick, easy and secure seal.