This module is now end of life and given the altitude limit can no longer be considered suitable for High Altitude ballooning with the newer latex balloons.
SiRFstarIII™ 20-channel GPS SMD compact module/receiver with enhanced high altitude power saving modes.
The ISM300F2-C5-V0004 module is programmed with HIGH ALTITUDE BUILD, ceiling 135,000 feet, and works at cold temperatures for balloon applications.
More information to come. Used on Ava flight computer. Project Ava
External link : ISM300F2-C5-V0004