Abstract: A connecting part for attachment on a mounting rail has a fastening part with an at least approximately rectangular cross-section. The fastening part has legs and surrounds when mounted a mounting rail on all sides by having a matching cross-section formed by the legs. The fastening part has clamping devices for effecting a clamping fixation of the connecting part on the mounting rail. A cross-sectional plane of the fastening part has two diagonally opposed corners and the clamping devices are arranged on the two diagonally opposed corners, respectively.

Abstract: An assembly rail has at least one profile element with support legs. A rail slot is defined between the support legs and extends in a longitudinal direction of the at least one profile element. The support legs are oriented inwardly toward an interior of the at least one profile element. A hollow profile that is larger than the at least one profile element has edge strips arranged along at least one longitudinal side of the hollow profile. Between the edge strips a receiving slot is formed. The at least one profile element is arranged in the receiving slot and is connected fixedly to the hollow profile. The rail slot of the at least one profile element opens outwardly.