Check the listing for details. Alpine RUX-KNOB.2 Remote Bass Control. Condition: New. Listed at 29.95 USD. Product highlightsremote level controller for Alpine amplifiers mono amps sub channel of 5-channel amps bridged channels 3/4 of the X-A70F adjusts gain from 0 to -12 dB multi-amp capable (standard phone cable splitter required — not included) 16' connection cable warranty: 1 year What's in the boxAlpine Remote Bass Level Control module 16.4' (5 meter) connecting cable (RJ-14 plugs on both ends) 4 Self-tapping screws (Length 1/2") About this itemWritten by Crutchfield's Buck Pomerantz Tweak the subwoofer volume from the driver's seat The RUX-KNOB.2 remote level controller works with Alpine's amplifiers so you can manage your bass level from the front of your vehicle. This handy little knob adjusts your amp's level from its set maximum volume all the way down to virtually "off." Since it adjusts level and not "bass boost," you'll maintain the same bass tone as you turn the volume up and down. You can control multiple amplifiers with a single remote by adding a standard phone cable splitter (not included).