... PowerDC3V or 2*AAAPower output31mvBatteryNot includedS/N50dBImpedance 8ΩProduct useSuitable for promotion gifts, business, home, school, outdoor, emergency ... on the rule, “people-first values”. Since then, we are aiming at self-planning, self-researching and developing new products. Only ... your attention. We are always here and we are all ears here, waiting for your suggestions. Sample Room: Office: ...