Aquatop’s Platinum Quartz Glass Heaters are completely submersible and ideal for use in both freshwater and saltwater environments. Featuring a user-friendly temperature control dial, these heaters efficiently and precisely warm your aquarium water between 68 and 93 degrees Fahrenheit. Their durable quartz glass construction offers versatile placement options within the tank. Additionally, the Quartz Platinum Heaters are backed by our Platinum Shield limited lifetime warranty. Designed for tanks up to 25 gallons.