James Robinson wears Pro Gear Shoulder Pads. Pro Gear pads aren’t nearly as popular as Xtech or Riddell shoulder pads but still used in the NFL. Pro Gear pads are pretty popular among Florida teams (Dolphins, Jaguars) because the company is based out of Jacksonville, Florida.
I can’t tell the exact model but these are definitely Pro Gear shoulder pads. My guess would be the PLS-10 because they are so slim and low-profile. From the looks of it, these are lightweight and offer a lot of range of motion. Range of motion is important for a running back because they need to be able to run between the tackles and catch the ball out of the backfield.
You can check out some of the different Pro Gear shoulder pad models here.