Yes it is a Rolleiflex 3,5 B (also called 3.5 MX-EVS in America) from 1954-55. It's the Type 1 which doesn't let you uncouple the EVS system. On the Type 2 from 1955-56 you could uncouple the EVS system.
I have one, 3,5 B, Type 1, with Tessar. Excellent camera.
I have a '55 MX-EVS, on the type 1 you can uncouple by continuously holding down on the detent button in the center of the aperture wheel. Very nice camera if like me you prefer using a hand held light meter.