When using handsets connected to these products there are two methods for Transferring Calls.
The correct method is dependent upon the type of Trunk which you are connected to during the call.
Please see attached document for full details and explanation of each method.
Or if you are simply using your handset behind a host PBX (Method 2) then this single page user guide will explain.
Also please find a tutorial video in the DECT PHONES section here.