The OT2m is the most widely used variant of the Tracker2. It uses mostly surface mount construction and is housed in the same powder-coated metal enclosure as the older OT1m.
PCB version 1.0 is in current production. Version 1.0 has a minor flaw - a resistor was omitted from the layout and schematic and is installed on all current OT2m units as an 0402 size part placed between two vias on the bottom side of th ePCB.
The OT2m has been replaced by the OT3m.