The Yealink DECT dongle DD10K enables T41S, T42S to work concurrently with the Yealink DECT system as a handset after pairing with Yealink W60B DECT IP basestation. Yealink T5x Series (ie Models T56A, T58A, T58V, etc) Firmware Version 83 (v83) or higher): The DD10K enables Yealink T5 series phones T56A, T58A, T58V to function as a base station which can pair 4 compatible Yealink Cordless Handsets (i.e. Yealink W52H, W56H, W53H) to be connected simultaneously. This allows you to setup a office without wires or cables Supported by a powerful transmission rate of 1152 kbps (1.2 M), this solution provides you with a quick and reliable DECT connection without wiring or cabling, and gives you the ability to get setup in minutes. As a complement to Yealink DECT series IP Phones, plugging the DD10K to the USB port on the Yealink IP Phone enables the wireless DECT feature. The Yealink DD10K meets CAT-IQ 2.0 standards. Wireless Range: â Indoor Range: 20m~50m (66ft - 164ft) â Outdoor Range: 300m maximum (984ft) (with clear line of sight between handset/phone, shorter range with obstructions or walls)IC: 1074 "This is a Global Teck exclusive offer." Bundle includes: â Microfiber Cloth â Yealink DD10K USB Dongle â Quick Start Guide â Important: If your Yealink T41s or T42s does not have firmware 66.82.0.35 you can update the firmware by logging into the phone using a PC/MAC. You will need to download the first download the firmware version 66.82.0.35 from Yealinks website. â Important: Yealink T5x Series (ie Models T53, T54, T56A, T57, T58A, T58V, etc) Firmware Version 83 (v83) or higher):