The Brand External Remote Knob XTBR25 Bass Boost Wired Variable Level Controller (secondary gain control), high quality product remote unit comes with 5Meter/15F long Flex remote connection wire/Cable and Bass Knob.
with the following Select Amplifiers:

Alpine PDX Amplifier: 

• PDX-V9

PDX Amplifiers:

• PDX-M12
• PDX-M6
• PDR-M65
• PDR-V75
• PDX-V9 

X-Series Amplifiers:

• X-A70F
• X-A90V
• X-A90M

MRX Series Amplifiers:

• MRX-M55
• MRX-M110
• MRX-M240
• MRX-M50
• MRX-M100
• MRX-M200
• MRX-V60
• MRX-V70

V-Power Amplifiers:

• MRV-M250
• MRV-M1200
• MRV-M500
• MRV-V500
• ​​Part Numbers:​​​​
• PWA-S10V
• KTP-190U
• S-A60M
• PD-RV75
• 820UXA-NQRE
• 82078H11482V78
• XTBR25
• RUX-Knob2

Technical Specifications:

• Brand Name: .
• Model Number: XTBR25-XT91579
• Cable Connector: 6PIN-STW
• Cable length: 5-Meter/16Feet/196Inch long Cable.
• Bass Knob Material: Metal
• Color: Black

Install Notes:

1. Plugging in the remote Bass Control overrides the BASS EQ Control on the amplifier side panel.
2. REMOTE LEVEL PORT: This is the connector port for the optional Remote Level Control. Now the amplifiers' secondary gai circuit can be adjustable from the driver's seat.

What is within the Package: 

1. Remote Bass Knob 
2. 5-Meter-long Flex Cable
3. Install Manual

Caution before purchase:

• Make sure the remote is exactly with your amp before purchase
  Brand Remote Amplifier Level Controller Optional bass remote XTBR25-91579
  Optional Wired Remote Volume Control with Select Alpine Series Amplifiers
  Controls the bass/gain from the front seat or remote location from amplifiers, without having to reach for the amplifier.
  Allows You to Adjust Your Bass Level Quickly and in the Most Ideal Location, Simple 1-wire connection gets you up and running in a flash.
  High Quality Product Remote Unit Comes with 5-meter/16 Feet/196-inch remote connection wire and bass knob and mounting Screws