100 pieces. 100pcs Black Courier Bags PE Plastic Poly Storage Bag Envelope Mailing Bags Self Adhesive Seal Plastic Pouch Mailers. No stretch. Sticky peel strip. Dimensions: 10.8cmx17cm approximate open length (these are the outside dimensions so please expect 13cm – 15cm effective length, depending on the thickness of goods inside). Ultra thin – approximately 1mm-2mm can be saved, enabling thicker items to be posted within Australia Post letter limits of 5mm ($1.20 postage) and 20mm ($2.20 postage). .