400W Aquarium Heater Anti-Explosion Submersible Fish Tank Water Adjustable temp control. BRAND NEW   Super Shatterproof 2 mm Thickness Quartz Glass] Maximum strength Quartz Silica Tube is shatter resistant & more durable than conventional glass heaters. [Durable Plastic Outer Sleeve] There is a durable thick plastic outer housing wrapping up the glass tube. Acting as a buffer between your fish and the hot heater with Non-conductive plastic outer sleeve so fish/turtle/plants can’t be burnt. [Suction Cups] The suction cups provided fit into the protective outer sleeve in a very unique way. They can hold heater vertical or horizontal under the water. Once installed they form a pressure fit around the quartz glass housing and the outer protective housing. [Thermostatic Control] This heater can automatically control the temperature. It will automatically turn off as the temperature rises above the internal setting you choose, and turns back on like once it sufficiently cools down. Specification: Diameter： Glass tube 0.94 inch Plastic housing 1.3 inch Cable length: 59 inch Heater length: 15.7 inch Power: 400W Adjustable temperature: 61°F~93°F (16°C~34°C). Operation instruction: The heater should be immersed into water completely. It takes about 10~15 minutes to get used to the water temperature. Then adjust and set the desired temperature value 61℉~93℉.