Square sub woofer, any good?

I am looking for a speaker that will fit my enclosure and I have found one that looks almost perfect but it's a square type.

It's not branded kicker, even though they do make a 10" I'm not really wanting to pay the asking price for one especially as I already have a bigger one which is used in the house for the theatre system and really shakes the floor and rattles the furniture. I think one of them in the car would be overkill really

Here is a link to it on eBay http://www.ebay.co.uk/itm/351526985725?ru=http%3A%2F%2Fwww.ebay.co.uk%2Fsch%2Fi.html%3F_from%3DR40%26_nkw%3D351526985725%26_rdc%3D1

Has anybody used these? Not a lot of info about them online so either crap or new.

Or can anyone please recommend me a better small woofer? preferably an 8" or shallow 10" budget wise I'm looking at the low end for now to see if the enclosure is any good as may have to start over.

Any input would be greatly appreciated. Thank you