Envelopes
Tyvek C5 Envelope 229x162mm Pocket Peel and Seal White (100 - 11790
Security envelope designed to be water and tear resistant. Made of 100% high density polyethylene fibres (HDPE). Extra strong hot melt peel and seal closure. Size: C5 (229 x 162mm). Colour: white. Pack of 100.
https://www.bizrate.co.uk/envelopes/tyvek-c5-envelope-229x162mm-pocket-oid32134166102.html