Here we have a Brand New Alpine SWR-2210D.   These are discontinued. 

Making harder to find in this condition.  

These were one of the earlier models.   Truly on of the best.  

Built for heavy-duty sound, Alpine's SWR-1022D 10" subwoofer delivers high-impact bass that you can hear and feel. Alpine has taken the best features from its previous Type-R Series subs and added advanced technology for ground-pounding power and superb accuracy.

The dual 2-ohm voice coils handle lots of power while offering system wiring flexibility. An aluminum die-cast frame provides a secure, non-resonant housing that won't color your bass. The SWR-1022D works well in either sealed or ported enclosures.

• 10" subwoofer with dual 2-ohm voice coils

• Kevlar® reinforced pulp cone with Santoprene™ rubber surround

• cast aluminum frame with perimeter venting

• frequency response: 24-600 Hz

• power handling: 200-500 watts RMS (250 watts per coil)

• peak power: 1,500 watts

• sensitivity: 83 dB

• top-mount depth: 6-13/16"

• sealed box volume: 0.5-0.8 cu. ft.

• ported box volume: 0.6-1.25 cu. ft.