出售黑色 HeadRoom AirHead 隨身型耳擴一組，使用三顆 AAA 四號電池做為電源供應，可連續使用達四十小時左右。亦可使用 AC 電源輸入（需自購變壓器，規格為 DC 9-12V、300mA 以上、-<+ 型式）。
主要規格如下：
- amplifierTypeID: Bi-Polar
- outputStageBiasingID: A/B
- volumeControlID: Rotary
- Pot numberOfInputs: 1
- lineOutputs: N
- loopOutputs: N
- inputImpedance: 31000
- outputImpedance: 0.0200
- maxGain: 3.7
- outputVoltageAtClipping: 1.7
- outputPower30ohms: 21
- outputPower100ohms: 10
- outputPower300ohms: 4
- thd10mwatts30ohms: 0.01700
- thd10mwatts100ohms: 0.01500
- thd10mwatts300ohms: 0.01400
- crosstalk10mwatts30ohms: 80
- crosstalk10mwatts100ohms: 80
- crosstalk10mwatts300ohms: 80
- 尺寸：H25*W70*D114mm