Mini Active Volume Control Knob Volume Controller, 3.5mm Volume Control Knob Speaker Audio Adjuster, For Watching Videos, Weddings, Celebrations, Conferences, Etc. - Walmart.ca
LINEPAUDIO A967 Full-balanced Passive PreAmp Active Speaker Two-channel Volume Controller(Black)
Preamp Active Speaker Volume Controller Rca Connector 128mm Fader Precision Volume Adjustment Controller Speaker Audio Adjuster - Electric Instrument Parts & Accessories - AliExpress
Amazon.com: Mini Active Volume Control Knob, 3.5mm Audio Adjuster PC Speaker Amplifier Switcher Volume Controller : Electronics