The quality NEC H81 TriStar DT330 750189 is a Corded earbud-style headset with a voice tube and quick disconnect. It requires NeCA-16 in- Line Amplifier 750609. 

It is an in-ear style Top only. Monaural with a voice tube transmitter, equipped with Quick Disconnect Cord, clothing clip, (4) ear tips, & spare voice tube.

Compatible with:

DT830/DT730/750 IP Endpoints (IP12/24/32-Button & 4-Screen DESI-less & Sophi models) DT430/DT330 Digital Endpoints (Digital 12/24/32-Button & 4-Screen DESI-less models)

*Can also be used with the DT410, DT310 and DT710 endpoints, but
will require the Plantronics Vista M22 Amplifier/Switch (not sold by NEC), as well as the A10-16 cable (750609).

*Requires the A10-16 In-line Amplifier Cable (750609) when used with DT430, DT330, DT830, DT730, and DT750 endpoints.

NEW Part# Q24-FR000000113121