An electrical contact assembly comprised of four identical modules arranged in a four-sided formation. Each module comprises of a bottom housing formed with two rows of through holes to allow a row of front and back contact pairs to be inserted, with separators in between each pair to prevent electrical conductance between the pairs. A top housing is then lowered onto the top of these contact pairs. With the aid of a key tool, the rows of contact pairs are inserted into through holes in the top housing. By virtue of different heights between the front and back rows of through holes, the front and back contact rows are inserted one first, and then the other. This allows for easier installation of an assembly with minimal tolerance accumulation.