PremierTeam pocket white 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. Box of 500 envelopes. 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 plain envelopes are solid for sending private documents without seeing the interior contents, and feature interior security printing. The self seal flap has adhesive on both sides for a quick, easy and secure seal.