Elements, couplers, systems, and methods for joining two or more trough members. A locking element for a coupler of a cable trough system includes a member including a first member end configured to be coupled to the coupler, and a second member end. The locking element also includes a locking member including a first portion slidingly coupled to the second member end of the member, and a second portion extending to a point, and a handle member defining a bottom surface and being pivotally coupled to the second member end of the member, the handle member pivoting between locked and unlocked positions. As the handle member is pivoted from the unlocked to the locked position, the bottom surface moves the locking member along the member so that the point of the locking member extends into a spacing formed by the coupler.