PJ7 Opaque Poly Mailers are among the largest in our range measuring 500mm x 353mm. This is big enough to carry a standard sized shoe box and is also ideal for sending bulkier items such as knitwear, bed linen and large tablet computers. To ensure our Poly Mailers are tear and puncture resistant we use extra strong 75 micron white polythene. The thick, durable polythene has a multi layer structure that provides reliable waterproof protection for items in transit. The other advantage of Poly Mailer bags is that they are extremely light so your postage costs are minimised. The PJ7 size weighs just 17g and comes fitted with a self-adhesive strip to make it extra quick and easy to pack securely.