GN 4150 amplified headsetAmplifier SpecificatonsFootprint: 5.1 in. (l) x 2.2 in. (w)Standard Features: Headset/Handset SwitchSpeaker Volume WheelTelephone/Computer SelectorMute ButtonMicrophone Volume SelectorTone adjustmentTelephone Compatibility SelectorData Port - 6 pin/ RJ11Indicators: Online indicator LED blinks when line ispicked up. Online indicator LED rapidblinks when headset microphone is muted.Host Phone Compatibility: All types of business phones must complywith RF immunity Spec. Carbon: switchselected by user Electronic: switchselected by user AT&T: switchselected by userPhone Connection: 4-pin modular plug/ RJ9Compliance: Complies with FCC Part 68Headset SpecificationMicrophone Type: Noise-filtering electretHeadset Connection: Gold plated 2.5mm connectorStandard Features: Pivoting boom armAdjustable headbandFlexible earwrapLeatherette & foam ear cushionClothing clipWeight (headset and cord)On-Ear Wearing: 1.11 oz.Over-head Wearing: 1.59 oz.