Aquarium Heater 100W Submersible Digital Display Mini Fish Tank Heater with LED Fish Tank Heater with Intelligent LED Temperature Display and External Temperature Controller, for 10-20gal Fish Tank INTELLIGENT TEMPERATURE CONTROL: An intelligent IC chip controls the heater temperature, making the temperature difference within 2ºF. Automatic constant temperature function, when water temperature reaches to specified temperature value, heater will automatically stop heating, when water temperature is lower than the set temperature, heater will automatically start heating. Provide the best living environment for your aquatic creatures. DIGITAL DISPLAY REMOTE CONTROLLER: Digital LED display shows real time water temperature. Heating temperature range from 68 to 91F. The remote-button controller adjusts the temperature without getting your hands wet. AUTOMATIC OVERHEATING PROTECTION: Once set the desired temperature, this fully submersible heater lights on red indicates that it is heating. It will auto shut off once it reach set temperature. If the heating rod temperature reaches 96.8F (36C), the heating rod will stop heating. The thermometer can observe the water temperature at any time. SHUT OFF WHEN OUT OF WATER: Please note that this a fully submersible aquarium heater for fresh water and saltwater tank, when the top part of the heater is out of water it will auto shut off and the led displaying Er. The product uses explosion-proof quartz tube and is equipped with a plastic anti-collision sheath to prevent your aquatic organisms from being injured by touching the heating rod. Our heating rods can be used continuously for up to 10,000 hours and can display the use time. Let you replace the heating rod in time to ensure the continuous water temperature. Shipping We offer FREE shipping on all orders within the Continental USA! We ship within Three business days of payment, usually sooner. We use a selection of shipping services such as UPS, FedEx, USPS etc. We ship WORLDWIDE, APO/FPO addresses or PO Boxes allowed IN SOME LOCATIONS. We ship to some of US protectorates free, not all. Pls check with us or we invoice your shipping. Local pickups and combined shipping options are not provided at this time. Return You can return a product for up to 30 days from the date you purchased it. Any product you return must be in the same condition you received it and in the original packaging. Please keep the receipt. Payment We accept payment by any of the following methods: PayPal, direct payments, credit cards. Please pay as soon as possible after winning an sale, as that will allow us to post your item to you sooner! Feedback Customer satisfaction is very important to us. If you have any problem with your order, please contact us and we will do our best to make you satisfied. Contact Us If you have any queries, please contact us via. We usually respond within 24 hours on weekdays. Please visit our store to check out other items for sale! Thank you for shopping at our store.