These Securitex Tear Resistant Envelopes feature an ultra-tough 130gsm tri-laminate construction with a layer of film sandwiched between two layers of paper. The envelopes are tear and water resistant for increased security in transit, and feature a simple, secure peel and seal closure. These C4 pocket envelopes are suitable for A4 documents and feature an expanding 38mm gusset. This pack contains 50 white envelopes.