Voltage:120v/60Hz or 220-240v/50Hz 5W UV Suitable for Aquarium Up To 125L 7W UV Suitable for Aquarium Up To 175L 9W UV Suitable for Aquarium Up To 225L 11W UV Suitable for Aquarium Up To 275L 13W UV Suitable for Aquarium Up To 325L 18W UV Suitable for Aquarium Up To 450L 24W UV Suitable for Aquarium Up To 600L 36W UV Suitable for Aquarium Up To 900L