Small power amplifier, microphone input compatible, with volume adjustment function. - Model: OU-15 Ⅱ - Brand: MASSIVE - Volume Adjustment: Yes - Input Terminals: Microphone input - Power Indicator: Red LED I was using it as an amplifier for a CD player until recently, and it worked without any problems within that range. Please note that I have not confirmed all functions. Included accessories are the power cord and input cord. Safe and careful anonymous shipping. It will be protected with cushioning material and shipped in a cardboard box. We do not accept price reductions, holds, or separate sales. If you are paying at a convenience store/ATM, please be sure to comment with your payment schedule. If payment is not received within 12 hours, we will unfortunately have to cancel the order.