These Ryman Heavy Duty Envelopes are C4 sized & come in a pack of 10. These envelopes are heavy weight to ensure documents are safe during postal transport & have a peel & seal closure making them easy to use & more hygienic than standard gummed envelopes. These 324x 229mm Ryman Heavy Duty Envelopes are a must have for any school, home or office as they can be used to send documents.