^ I used to have one that looked similar to that, and i have to say, after 2 years of solid use, it started to leak... and not just at the seals either... the UV light some how weakened the plastic housing near the inlet at the bottom and started to leak water (luckily very slowly) so when i caught it i turned it off, and un-plugged my filter...
When i finally got a new UV light, i made sure it was a metal housing, but as for the old one, when i put my finger over where the leak was, i could feel the hard plastic had become extremely soft and when i pushed it a little harder, the weakened area literally just cracked open...
So i guess over all what i am trying to say is, stay away from any unit that looks like this... although in my case it could have just been bad luck?