Section 42 (Instrumentation/Driver Info): Tachometer: Specification
WARNING: This page is about a different car, the 2015 Subaru XV Crosstrek and 2015 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.
Since the meter - main assembly cannot be disassembled, do not remove or inspect the tachometer alone. (Do not remove the cover on the back surface.)