Ideal for mailing bulky items such as catalogues, reports and brochures, these E-Green mailer envelopes feature a 120mm 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 100 envelopes, each measuring 500mm x 400mm.