As per Wilko, it's not clear if you mean the 230V version of the device operating on 120V (which as he says, probably won't work) or a 120V version of the same device, which would indeed require 50A.
However, many USA electrical installations have a 120-0-120V configuration, meaning that while small appliances and lights operate at 120V from hot (line) to neutral, 240V is also available between the two hot (line) wires. Equipment of this kind of power rating is most commonly arranged to take its power at 240V rather than 120V and hence would consume 25A. One could use a 30A, 240V branch circuit and NEMA 14-30 4-prong plug and receptacle, which is the current standard for clothes dryers for example.