Ideal for mailing bulky items such as catalogues, reports and brochures, these E-Green mailer envelopes feature a 50mm gusset. Made from 120gsm Kraft paper, the easy to open mailers are waterproof and feature a return strip as well as a peel and seal closure for a quick, strong seal. Supplied in a pack of 250 envelopes, each measuring 350mm x 250mm.