Poly Bubble Mailers 8.5 X 11 Inches or 23X28cm 40Pcs Bags Pack, Strong Adhesion Self Sealing Padded Shipping Mailing Envelopes Bulk Perfect Size Mailers Bubble envelopes are crafted with 120gsm polyethylene materials and reinforces sealing on the edge, making them not easily punctured and damaged. Each mailer is equipped with a strong self-sealing adhesive strip that is tamper-resistant and tamper-evident. Padded poly bubble mailers are an alternative to standard packaging. Opening adopts the adhesive tear strip for a tight, secure seal. Peel and stick make the packing process more convenient. Non See Through strong light, the items in the padded mailers cannot be seen, which can protect your privacy well.