K-Lock™ Insulated Shipping Boxes are made from high quality EPS and are available with or without an outer shipping carton.  The lid of the cooler is designed with a grooved ridge that allows it to “lock on” for superior insulation.  This, combined with the “K-value” associated with  low thermal conductivity is where K-Lock™ products get their name.  The unique design and high quality materials allow K-Lock™ packaging to satisfy even the most rigorous distribution requirements and package qualification standards.