The Velcro on the back makes it easy to use, but please remove it if you don't need it. Product Description Applications: Ideal for mixing multiple mono or stereo sound sources into a single mono signal. Suitable for use in karaoke, rehearsals, home studios, etc. Useful for connecting CD players, synthesizers, line outputs of bass amplifiers, etc., to tape decks and other devices. Passive Design: Adopts a passive circuit that does not require power, achieving clean signal transmission without adding noise or distortion. The simple and robust design makes it a reliable and easy-to-use device. Operability: Equipped with rotary level controls for each channel, allowing individual volume adjustment. Intuitive operation, no special settings or expertise required. Connectivity: All inputs and outputs use 1/4-inch phone jacks. Compatible with line signals as well as high-impedance microphones and electric instruments. Main Specifications Number of Channels: 4 channels (mono mixing) Input Impedance: 47kΩ Output Impedance: 12kΩ Gain: Up to 12dB Connectors: 1/4-inch phone jacks (input and output) Dimensions: Approximately 90mm x 70mm x 40mm (3-3/4 x 2-3/4 x 1-1/2 inches) Weight: Approximately 454g (1 pound) Features: Passive design, no external power required, compact and easy to carry, robust construction for high durability. Special Notes The PowerMIX I is a product that emphasizes simplicity and cost-effectiveness, ideal for environments that do not require complex functions. Because it is a passive mixer, it cannot amplify the signal like an active mixer, but it provides clear mixing while minimizing signal loss. Reviews generally include evaluations such as "Performs as expected, not flashy but reliable" and "Simple and easy to use." On the other hand, it is necessary to understand the gain limitations due to the passive design and use accordingly.