Boxes Fast offers a large variety of insulated cartons and refrigerated gel packs to choose from. Boxes Fast BFRB7 re-freezer-r-brix cold bricks 4 1/2 x 2 x 1 1/2 inch (L x W x H) are great for shipping pharmaceuticals, blood products, lab samples, bio products, meat, seafood, and food products. These cold packs protect against thawing by keeping perishables chilled at a uniform temperature for over 12 days. Formulated with food safe, non-toxic materials sealed in a heavy-duty plastic pouch.