These high quality q connect internal mail envelopes feature a reusable self sealing flap to make sure documents are kept secure during transit they also feature punched holes to show at a glance if theres a document inside and include pre printed boxes for clear addressing to the intended recipient sturdy 200gsm construction ensures long lasting use manilla envelopes for internal mail punched holes show if envelope is in use reusable self seal flap printed boxes for addressee size c4 32