Just the Ballast, 3 wattages, not a common purchase.
Ultraviolet Ballasts - Size Options
Each Ballast must be used in the correct system! Please check your Ultraviolet Sterilizer wattage before purchasing a Ballast!
Easy to install. Each Ballast attaches to the Bulb via the four progned end of the cord. Your tank comes with them pre-installed, so mimicing the it is will help with installation. Clean Cotton Gloves must be worn when handling the bulb, and will be provided. Please do not touch the bulbs with bare hands, oils from hands will damage your bulb!
Ballasts have two parts that twist on and off. The Smaller twisting part tightens the cord. The Larger twisting part connects the cord to the U.V.S. Housing. Make sure both are on correctly and are slightly tighter than finger tight.