100pcs/lot Practical Stick-on Dual Scale Digital Aquarium Fish Tank Thermometer change color Temperature Sticker Black Features: Brand New Color: as shown by photos (Real color could be a little bit different from stock photos due to screen reflection) Package list: NO Retail Box. Packed Safely in Bubble Bag. Material:Plastic. Unlike traditional thermometer that takes forever to figure out where that little red bar in the tube sits. Size is just right for any Aquarium. Easy to install, just peel off the back of the sticker and the transparent protective film at the front and stick it on the outside wall of the aquarium, that is it. No battery and suction cup to worry about. Measuring range: 18-34 C / 64-93F. Place on the tank glass outside the aquarium tank Suitable for cold water, tropical and marine aquarium. Both Centigrade Fahrenheit.