A module for in-line arrangement on at least one further module in a fluid power valve cluster (10) including modules placed in a row adjacent to one another in an in-line direction, comprising communicating means for communication with the at least one further module of the valve cluster (10). For the there is such that the means are designed as waveguide communication means (19, 21 and 23) for communication via a waveguide (14) of the valve cluster (10).