＜Features＞ ■ 4-channel headphone amplifier ■ Independent volume control for each channel. Allows for optimal volume adjustment for each headphone. ■ Very lightweight and compact size. Doesn't take up much space for carrying or storage. ■ Detachable rubber feet allow for removal depending on how you use it. ■ Includes a power adapter. ＜Specifications＞ ■ 4-channel headphone amplifier ■ Output: 6.3mm stereo standard jack x 4 ■ Input: 6.3mm stereo standard jack x 1 ■ Frequency response: 50～20,000Hz ■ Size: 129 x 30 x 83 mm (W x H x D) ■ Weight: Approximately 250g 4-channel headphone amplifier, CP4H model, offering high-quality sound in a compact design. I purchased this but never used it and have been storing it. I opened the box to check the contents, but I haven't taken the unit out. It is unused. Please understand that there may be some box staining from storage. Thank you for looking.