I was looking for a hand-operated in-line 3.5mm stereo jack volume control, simple, easy and quick to dial up or down, for a quirky and unconventional application. The Behringer Monitor 1 has turned out to be the perfect solution. I have two acoustic-electric rigs, one is a full-on mains powered live looping / amp performance set-up and the other is a battery-powered rig (vintage Zoom A2 - Behringer MX400 - Boss BR-80 - JOYO AC20) for spontaneous quirky busking whilst touring on my solar augmented electric cargo bicycle. Yes, I use the batteries on my electric bike to power the music rig. Playing various instruments in-studio, I record bass-line / harmonies/percussion onto the Boss BR-80 to create my busking backing tracks. When on the road, these can be played back via the BR-80 using the Monitor 1 as a remote volume control plugged directly into my amps 3.5mm stereo AUX input. I could use the volume control on the BR-80, but being so small it's difficult to access and accurately adjust. The large knob on the Monitor 1 solves this problem, and being passive it's one less thing that my batteries need to power. Easy on the wallet, easy to use with multiple connectivity options, passive and compact, it fits all my needs. And as usual, promptly and conveniently delivered to me thanks to Modern Musician's incredible online service. Cheers guys!