SUPERIOR ICE RETENTION: CORE HYPERCOLD(TM) Insulation keeps contents chilled up to 3.5 days, using high-density EVA foam to retain cold, combined with reflective mylar film to repel heat. LEAKPROOF: Guaranteed to be 100% leakproof thanks to the patented TRUA(R) Zip waterproof zipper along with fully welded seams inside and out. DURABLE CONSTRUCTION: The rugged TPU shell is both abrasion and puncture resistant ensuring years of use. PORTABILITY: Side handles, a shoulder strap, and top carry straps create convenient transportation options. ADDED STORAGE: A front, water-resistant zippered pocket stores small personal items.