Thank you for viewing. Regarding this item, the following operational checks have been performed: Power → ○ Inputs → 3 systems ○ Paging input → ○ Speaker output → Low and high impedance both ○ Microphone input → ○ It can be used without any problems, so you can purchase with confidence. Contents: Amplifier unit, outer box (for a different model), stereo pin plug, stereo mini-pin plug, AC cord OE-M15 power amplifier with microphone volume adjustment function. - Model: OE-M15 - Brand: MASSIVE - Input terminals: AUX1, AUX2, USEN - Volume adjustment: Microphone volume adjustment available - Power supply: AC power - Status indication: ON/NORMAL, BLINK: OVERHEAT