That type of carb is for their special Helicopter engines. it is used on engines like the OS Hyper 55HZ-R DRS heli-engines.

DRS system delivers fuel to the regulator under constant pressure
for precise fuel delivery throughout the entire tank from full to
empty. Mounting position of DRS is perfectly in line with the carb for
consistent operation in all attitudes of flight.
Dual needle 40L-R carburetor allows independent adjustment of idling,
hovering and high speed with four arm throttle lever for use with
a variety of servo brands.