The Delta Mug and InsulMug along have been designed by Sea to Summit to be the ultimate expedition/outdoor kitchen -ware. Our patent pending Protex™ hex pattern base disperses surface temperature whilst the EVA ThermoSkin™ on the InsulMug ensures your drink retains heat without being too hot to handle. The hollow, cool-grip rim provides another ergonomic holding option, so the mug maintains a low-profile without the need for a hard-to-pack handle.