The Delta Series by Sea to Summit is designed to be the ultimate expedition and/or outdoor dinnerware. The patented Protex hex pattern base reduces surface heat so food and drink are never too hot to handle. Food grade, BPA free Nylon 66 material has an incredible strength to weight ratio. It is impervious to odours and stains and it will not crack in the extreme cold. The lightweight Delta Insulmug features a groundbreaking advancement in thermal insulation by incorporating a moulded PU sleeve and a leak proof sipper lid. It is ideal for expeditions, camping and daily commuting. The Delta Mug and Delta Insulmug have hollow, cool to grip rims to provide an ergonomic holding option, which creates a low profile and stable design without the need for a handle, which is hard to pack. The Delta Insulmug uses an EVA ThermoSkin sleeve and dribble proof sipper lid to keep hot drinks steaming. And finally, measurement increments feature inside all models for campsite culinary needs.