The switch boards are assembled so that only the Short levered switch is the momentary. The other switch is a three position with a long lever.
Within the X-Lite, Switches SA and SC and SB and SD are pre-soldered to their respective PC boards and as a result need to be replaced in pairs (see pics). Only the short levered switches are momentary (SC & SD), the long levered switches are three position.
Switches SA and SC are the Left Hand pair (Transmitter Left).
Switches SB and SD are the Right Hand pair (Transmitter Right).
Choose Left or Right from the drop down menu above to choose the pair of switches you would like to purchase.