Penguin Expanding Insulated Mailers – Revolutionary space-saving insulated envelopes that arrive compressed at ~0.5” thick and expand to nearly 3” for superior thermal protection and cushioning. No outer carton required. From America's Packaging in Chicopee, MA. Contact Us for a Free Quote.

Why Choose Penguin Expanding Mailers?

 

This innovative Coldkeepers Penguin Expanding Insulated Mailer transforms how you ship temperature-sensitive items. It ships flat to save warehouse space, then expands into a custom-fitting insulating cocoon around your product and PCM refrigerant — delivering exceptional thermal performance and crush protection in one efficient package.

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Key Benefits:
 

• Space-saving & efficient — Compressed design reduces storage and inbound freight costs.

• No outer box or void fill needed — Ships as a complete, ready-to-use insulated envelope.

• Superior insulation + cushioning — 1 3/8″ foam layer sealed in durable 4.5 Mil metallized liner for outstanding thermal protection and impact resistance.

• Tamper-evident & secure — Leak-proof zipper + pressure-sensitive tamper-resistant tape.

• Fast & easy — Quick loading, sealing, and labeling for higher packing efficiency.

• Form-fitting protection — Adapts to irregular shapes and expands to cradle contents perfectly.
   

Available Sizes
 

• 9″ x 12″ Penguin Mailer

• 12″ x 16″ Penguin Mailer

• 15″ x 20″ Penguin Mailer
   

Ideal For
 

• Pharmaceuticals, biologics, and temperature-sensitive medications

• Premium chocolates, seafood, meats, cheeses, and perishables

• Vaccines, specimens, and diagnostic kits

• Direct-to-consumer and e-commerce shipments
   

Innovative protection that saves time, space, and money. Contact America's Packaging today for custom sizes, PCM recommendations, bulk pricing, or a free quote. We provide complete cold-chain solutions including gel packs, thermal liners, and insulated shippers.