Hitop 50W 100W 300W Calentador de acuario sumergible ajustable para tanque de peces de 5-50 galonesExplosion Proof: 2mm thickened explosion proof glass, 33% thicker than the normal, safer for both human and animals. Application: 300W water heater is suitable for 20 50 gallon tank, also suitable for both saltwater and freshwater. Accurate Temperature: Temperatures from 68F to 93F (20C 34C), come with a thermometer sticker, convenient to detect the water temperature without another pay. Long Service Life: Adopt 10 slot multi branched heating wire