💦- 100% Waterproof : With Sealed Ring Design, Fischuel Aquarium Thermometer can completely submerge into the water, water temperature measurement is more accurate. ( Your Betta can also use it as a rest leaf.) | ✋- Suction Pad For Ease Of Placement : Just find the best spot in the fish tank, then attach the unit with the small suction pad which will keep the thermometer in place until removal is required. | 🐳- Extreamly Easy To Use : No instructions necessary. This is the simplest aquarium thermometer on the market with no buttons to operate. | 👊- Durable : Powered by a LR44 battery which is very long lasting and easy to replace.（Batteries included） | 🐟- Wireless : Fischuel Fish Tank Themometer works precisely without any external wire and probe, makes your tank look clean and tidy and expand the activity space of your fish.