1OUTPUT LEVEL CONTROL: Stereo sound amp is compatible with 5mm and 6.35mm headphones, with output level control for each channel, can power up to four pairs of headphones and up to ten independent volumes. 25MM HEADPHONE OUTPUT: Headphone amplifier is designed with a power switch and a 5mm headphone output. When a recording session calls for everyone's heads and ears to be in the game, it is the perfect solution. 3EASY TO CARRY: 1 in 10 out headphone amplifier is easy to carry and suitable for the studio and stage. Can power almost any headphones, and power four headphones at the same time. 410 CHANNELS: With up to 10 different people in the studio listening to the master mix while recording, each listener can use the dedicated output volume control to determine how loud they want to be. 5NOTES: If you're tracking multiple musicians at the same time, or if everyone in a group wants to listen to a playback, you'll need a monitor distribution system.