Features:Freezer Safe: This mug can be it could also used in the freezer if you are trying to cool your drink down.Simple to Use: The mug is really easy to use simply twist the top membrane around and watch as a seal is quickly formed over the top of the mug.Keeps It Hot or Cold: Each mug is can hold up to 300ml and are double walled!Keeping drinks hot for 2 hours and keeping drinks cold for up to 6 hours.Twist Top Lidless Design: Using a silicone membrane and a revolutionary design there is no lid to this new mug. Instead you simply twist the silicone membrane over the top of the mug and watch as the seal is formed.Leak Proof and Even Holds A Straw In Place:The silicone membrane is adjustable leaving enough room for a straw to fit through the top. Simply put the straw in the opening and twist the membrane closed until the straw in snug in place. With a new seal there will be no liquid falling out of the mug.Notice:Actual color may be slightly different from the image due to different monitor and light effectPlease allow 1-3cm deviation due to manual measurementSpecification:Material:PP,Silicone filmSize:16.3x8.5x6.3cmCapacity: 300mlTemperature resistance: -10-100 degree centigrade