Mechanical or Solid State Switch for 48V DC and 2 Amps current
An SPDT able to support 48V potential difference and 2A continuous current may be a bit beefy (physically). If you must have a smaller switch for the user to interact with, you can use a small switch to activate an SPDT electromagnetic relay switch that supports 48V, 2A. There are power FET's that can get the job done as well.