Clear Audio - No Feedback or Background NoiseMakes Voices Clear and Easy To UnderstandRechargeable With A 48 Hour Battery LifeWorks At Home, Church,Restaurants and MoreComfortable Fit and Can Be Work With Glasses Specification:Weight: about 8gCurrent consumption: 1.2mAWorking time after being fully charged: about 40HMax. saturation sound pressure level(SSPL):130dB4dBFull on Acoustic Gain:F=1600Hz,455dBTotal Harmonic Distortion(THD):F>1000H 15% FFrequency Response:450-3500 HzEquivalent Input Noise:32 dBBattery:RechargeableBattery Current Drain:4 mAEstimated Battery Life:48 HoursRated Voltage:D.C 5VPackage Include:1Pc Or 1 Pair x Hearing-aidYou can choose the goods with or without plug,please choose the rihgt oneNotice:1.Due to manual measurement, lighting shooting reasons and the real thing will be slightly different, please understand.2. Due to the lighting effects and shooting angles, the color of the item and that shown in the picture might have a nuance.