The most technically advanced aquarium heater available delivering wide temperature control with LED warning alert system. Features: -Fits as intake tube to all RENA SmartFilters and RENA Filstar xP1 through xP4 Canister Filters or by itself as a conventional heater -Patented interactive display LED lighting with "abnormal temperature" alert flashes fast when water is +/- 5°F from set -Made with high quality, durable and unbreakable plastic meeting UL standards. Safe to touch even when heating -Energy-efficient tubular design heating both internal and external surfaces of the heater -Super accurate set up temperature knob with wide temperature range (69°F–93°F)