Router nodes do little sensing to save power but normally have a better antenna, which is raised on a tripod to link-up longer radio hops.
They have the same electronics so they could use the same sensors externally as the other nodes. Router1 which is on the ridge also has a slightly higher capacity battery as it handles the most radio traffic.
This is Router1’s antenna with its 3km view down to the estate buildings (white) where the final “border router” is located.