These Ryman Heavy Duty Gusset Envelopes are C5-sized and come in a pack of 10.These envelopes are heavy weight to ensure documents are safe during postal transport and have a peel and seal closure making them easy to use and more hygienic than standard gummed envelopes. They are ideal for sending bulky documents such as brochures, catalogues and information packs as their gusset design creates more internal room. These C5 Ryman Heavy Duty Gusset Envelopes are a must have for any school, home or office as they can be used to send documents with a significant amount of pages.