MDL LaserAce Rangefinder with compass module.
Trick on communicating with Terrasync, from Pete Christian:
To get the laserace 300 to connect to the 2008 geohx trimble: First and foremost, the password is 0 not 0000, or 1234. To connect go to the bluetooth menu under settings, under devices select 'add new device'; it will search for and find the rangefinder. It is called 'LA300'. Select LA300 and hit next. Input the correct password = 0. It will say that you are connect but the device will be under the 'disconnected' area on the next screen.To connect you have to adjust the 'COM ports' settings on the top menu bar under COM ports the rangefinder will show up as it's own port, (COM5). Select it and hit OK. Open terrasync and go to the 'setup' menu => external sensors and select 'laser'. Open the properties, change 'port' to 'COM5: LA300", select done and you should be ready to go!