RCF LF21N451 21" Subwoofer...

Hello. I have for sale an RCF LF21N451 21" subwoofer. Acquired about 3 months ago, but it must go because it has been replaced. It will do nicely in a 3 cu ft. sealed application for rooms 1200 cubic feet and less [to 10Hz]. 8 ohms, so virtually any amp will power it, including the QSC usa 900 I used (900W). 13.2 mm Xmax [one-way], with 58 mm Xmech [peak to peak], Sd 1730 cm^2, 4.5" inside/outside voice coil, 3000W. $250+ shipping.