Selling a pair of Polk f/x 300i DIPOLE/BIPOLE surround speakers in "like New" condition. They are quite heavy. For subtle, detailed surround effects for your high-performance home theater, check out Polk's f/x 300i dipole/bipole speakers. You'll enjoy a great mix of direct and indirect sound, thanks to the 45º angled driver arrays. Housing a 3/4" silk dome tweeter and a newly redesigned 5-1/4" Dynamic Balance® driver on one baffle, and a second matching tweeter on the other, these little gems really sparkle. A dipole/bipole switch changes the phase relationship between driver arrays for lots of placement flexibility. Also includes a keyhole slot for wall-mounting. Reviews: http://www.audioreview.com/product/speakers/surround-speakers/polk-audio/f-x300i.html Dipole/Bipole Switch: There is a switch that allows the speaker to be used as a Dipole (out of phase) or Bipole (in phase) speaker. Wall Mounting: There is a mounting bracket attached to the rear of the speaker which allows it to be mounted to a wall using the supplied screws and keyhole slot. Due to the weight of the speaker, the screw must be driven into a stud, or a 25 lb. wall anchor (not supplied) must be used. Frequency Response: The overall frequency response is 50Hz-22kHz, -3dB frequency response is 55-20kHz. frequency response 55-20,000 Hz (-3dB) 8-ohm impedance sensitivity 89 dB handles up to 100 watts 5-way binding post connectors vinyl finish 12"H x 9"W x 8-1/2"D