Chuchubaby is brand from Japan which has more than  40 years of experience in manufaturing mom and bany care products like feeding bottles, baby wipes, breastpad, bottle wash, etc at affordable price with good quality.The temperature gauge let into suitable temperature of water for powdered milk by colour alterationStep 1: twist up and stick on the bottle with display surface upStep 2: fill boiled water into the bottle (when right side character plate is discoloured to green(70c).it is time to put in powdered milk.Step 3: Cool down for a while. When left side character plate is discoloured to green (40c)  it is time to feed.(Made in Japan)Contain : 1 pcs ( Reusable )