The temperature can be adjusted from 20C - 34C (68F - 93F).High heating speed, perfect double waterproof and full submersible design, heat resistant.Convenient installation, simple operation, high temperature resistance.The aquarium fish tank heater is easy to use with adjust knob and suction cup(can be both vertical and horizontal).Suitable for use in fresh water and sea water.Specification:Material: GlassPlug: USPower(As You Choose): 50W/100W/200W/300WSize Chart:50W: 195x25mm/7.68x0.98 inch100W: 250x25mm/9.84x0.98 inch200W: 295x25mm/11.61x0.98 inch300W: 395x25mm/15.55x0.98 inchPackage Includes:1 Piece Aquarium Fish Tank HeaterNote:1.Please allow slightly error due to manual measurement.2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.3.Wish you a wonderful on-line shopping Specifications: Material: GlassPlug: USPower(As You Choose): 50W/100W/200W/300W Size: 50W: 195x25mm/7.68x0.98 inch100W: 250x25mm/9.84x0.98 inch200W: 295x25mm/11.61x0.98 inch300W: 395x25mm/15.55x0.98 inch Note: 1.Please allow slightly error due to manual measurement.2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.3.Wish you a wonderful on-line shopping Package included: 1 Piece Aquarium Fish Tank Heater