Amazon.com: NVX XCR1 Dash Mount Wired Remote Level Bass Control Knob for Select NVX and AudioControl Sound Processors : Electronics
FOCAL CAR AUDIO REMOTE KNOB WIRED BASS SUB CONTROL for SOLID 1- 4 AMPLIFIERS NEW | eBay
Replacement Bass Controller Car Audio Adjustable with 6 Pin Subwoofer Extension for Remote Amplifier Bass Control Button - 3.8m : Amazon.com.be: Electronics
What type of wire connector is this? Goes to the Subwoofer GT-BassPro12 : r/CarAV
LCV Universal Bass Knob Level Controller with Built-in Digital Voltmeter, Blue LED Display, Remote Gain Control, On/Off Switch, Prevent Damage to Your Audio Equipment - Recoil Audio