They gavita are industry standard mate always wanted one or 2 but the money is big. They claim to give more light for your buck too due to there being no losses alongf leads etc, the ballast more or less attaches to the bulbs.
i have this ballast, 3rd yr (i think) on it and its been great. The 400v thing (dont quote me) gives a better coverage ort some guff. I dunno i just liked the sound of it.
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