Isnt my cab. Use it, and tell us how it works with your 400w HPS.

By the way, in the same web pag you linked, there is a 12V fan, very silent, cheaper and from 8,7 to 28 dBA. Less flow, but in any case, you will need more than one if you want to use it with a 400wHPS. By the way, the 12v fan consume 1/5 of the 110v one. And you will need a electronic regulator if you want to regulate it, rather than the 12v.

And i insist about axial fan arnt good when ducting is required. Isnt the same 81CFM from an axial fan than from a tubular blower. Any kind of turbulence reduces the fan flow far more than the tubular.

Only trying to apport constructive comments for my experience. Use it or not (thats the last suggestion my patience endure), but if you dont like my answer, please ignore it, but dont blame me or my english or whatever you prefer to critize. Take from my experience what you want, and simply ignore me if you dont like my comments.

Period