The three black dots are silicate gaskets, which stabilize the temperature.Slight color difference should be acceptable due to the light and different screen.Material: glassStyle: Nordic styleColor classification: black, white, green, red, coffee colorPopular elements: small and freshLarge-capacity double-layer insulation pot.24h long-lasting heat preservation, one pot of drinking water for one family.1*Insulation potThere may be 1-2cm difference according to manual measurement.We provide best product and service, if you have any problem, please let us know, we will solve the problemVacuum Insulated Water Bottle for Home, Office or Car,