The most simple but delicate appearance and the most simple but paractical structures. 1 The four fasteners on the top lid hold the container tightly , prevent deformation and guarantee tightness. 2. Leafproof and airtightness: Hight quality tpr secondary injection molding technology design for inner ring lid prevent leakage and keep durable. 3. Feature: Microwaveable and dishwasher safe 4. Technology: Used secondary injection molding technology , material is use the tpr plastic seal gum not the silicone. Advantage:why use this technology? 1)it will take the appearance of product more beautiful and creative , different with traditional shell in the normal market. 2)it is difficult to fall off while long time using, depend on secondary injection molding technology with tpr plastic seal gum. 3)comparing with secondary injection molding technology , ordinary silicone gum is easy to fall off while long time using