The MaxHeat o20 is the most powerful thermal-fusion weapon in the base game (before purchasing the Valkyrie add-on). Just like all other thermal-fusion weapons, the MaxHeat o20 will home on a target if the scanner has locked on the target, making it very useful when aiming is not easy. The MaxHeat o20 is the successor to the ReHeat o10 and is the second most powerful weapon in the thermal-fusion series.