Logitech Z213 3 Piece 2.1 Speake System w/ 4 Speaker System with 4" Subwoofer (Certified Refurbished) This Certified Refurbished product is tested & certified by Logitech to look and work like-new. The product includes all original accessories, and is backed by a 90 day warranty Down-facing subwoofer with a 4" driver provides a rich bass Separate bass control knob on subwoofer Built-in Headphone jack on control pod so you can listen in private Convenient control pod lets you adjust the volume and power