Visbr Professional Over-the-Head style RJ9 call center headset with noise canceling microphone. Business desktop telephone headset for office telephones have phone jack like headset port (RJ9, RJ11, RJ22). Compatible telephone brands: (IP7g Universal IP Phone, X16, X25, X50 phone sets) and more.This office headset comes with volume control and mute function on the headset cord. Visbr Call Center Headset is light in weight, comfortable to wear for long time and super clear voice quality. It makes you everyday works easy and comfort.This business telephone headset is a RJ9 monaural headset with rotatable microphone. The microphone boom is flexible, user may adjust it anytime. The headset band is adjustable. To use this headset with desk top phones with RJ9 headset jack, simple connect the headset to the headset jack, press the headset button on the telephone keypad. Adjust the switch on the headset cord until you can hear dial tone from the headset speaker. Make a test call. If other end can’t hear you, adjust the same switch again make sure both end can hear. Then, adjust the headset volume till you feel comfortable. Headset quick instruction printed on the button of the headset box. (RJ9 headset jack or RJ22, RJ11 jack, looks like telephone jack.)This office headset comes with 1-year warranty.compatible with following telephone models: T21p, T21p e2, T22p, T23g, T23p, T29g, T41p, T41s, T42g, T46, T46g, T46s, T48g. Compatible with GXP2170, GXP2160, GXP2140, GXP2135, GXP2130, GXP2124, GXP2120, GXP2110, GXP2100, GXP2020, GXP2010, GXP1450, GXP1200, GXP1400, GXP1405, GXP1610, GXP1615, GXP1620, GXP1625, GXP1628, GXP1760, GXP1780 & GXP1782Many more phone brands and models are compatible but not listed for the limited space.