Sunsolar Energy Technologies TLP-US Tell-All temp recorder with Floater Accurate Digital Readings with Easy to read Graphs Logs up to 100 days of Max/Min Temperature data-F or C Each unit comes with its own clear waterproof case for submersing in water for accurate readings. Great for Pools, Spas, Aquariums, Ponds, etc. Batteries Floater and Tether included