Based on this product's specifications, here are some alternatives and similar models
Mailing bags MAILmedia I19 White 56 g, size 320×455 mm
Summary description:
Poly mailer envelopes MAILmedia I19 in white, weight 56 g and dimensions 320×455 mm. Designed for shipping clothing, soft goods and similar items, these lightweight, tear-resistant mailing bags provide basic protection from moisture and dirt. Self-sealing closure speeds up packing; suitable for e‑commerce, retail returns and postal shipments.