Beam Communications, PTT100. The DriveDOCK Extreme hands-free docking solution provides a high quality transport installation using the Iridium Extreme® PTT Service. Combined with BEAM’s Wireless Push-To-Talk (PTT) rugged Handset Accessory Kit, it extends the power of the Extreme® PTT Device to the palm of your hand, in a vehicle. Additional Wireless Handset for EXTRM-PTT-W1 or to add wireless handset ability to the 9575 Vehicle Dock. NOTE: requires a PTT500 Multi Unit Interface.