GNU GPL INFORMATION 
Yealink T5X series IP phones firmware contain third-party software under the GNU General Public License 
(GPL). Yealink uses software under the specific terms of the GPL. Please refer to the GPL for the exact 
terms and conditions of the license. 
The original GPL license, source code of components licensed under GPL and used in Yealink products 
can be downloaded online: 
http://www.yealink.com/GPLOpenSource.aspx?BaseInfoCateId=293&NewsCateId=293&CateId=293.