Package quantity: there are 20 pieces digital temperature sticker in the package, enough quantity to meet your long time using and use for different occasions; The adhesive temperature strip measure approx. 13 x 2 cm/ 5.1 x 0.8 in in length and width, proper size to fit most surfaces "Easy to stick: our aquarium thermometer sticker features adhesive design, just peel off the tape and attach to surface of aquarium, fish tank and others; After about 2 to 5 minutes, the colored change will indicate the exact temperature; Please keep it away from any heat source" "Easy to read: the fish tank thermometer strip has 3 colored marking that can indicate the temperature situation, which can change with the water temperature, each color represents different water temperature condition, they can be seen clearly and quickly from the surface" "Monitor temperature: our digital temperature sticker is suitable for monitor temperature of fish tank and aquarium, can keep fishes, shrimps, reptiles or turtles comfortable by making sure the water isn't too hot or too cold; Also can be applied to measure the temperature of your DIY drinks and wine barrel, terrarium and any sort of pet tank" Measuring range: the stick-on digital temperature strip measures both Fahrenheit and Celsius degree, Celsius degree in the range of 18 to 34 C, and Fahrenheit degree in the range of 64 to 93 F