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.