Yamaha have released a series of professional bass amplification, consisting of one head, several combos and several cabinets.
This 4x10" cab (with level control for the tweeter) is rated at 300W. The impedance of 4? means you can hook 2 of them to Yamaha's own BBT500H Head, or get all the power from your 4? head.
Its 4 casters and low weight (only 24Kg) make it a breeze to move around.
To top it all, the price is great. No doubt the best cab in this price range.