A device for tensioning at least one essentially sheet-like plate or printing plate around essentially the surface area of a printing cylinder, wherein the printing cylinder is mounted so as to be rotatable about its axial rotational axis, comprising at least • a first rail that essentially extends parallel to the rotational axis of the printing cylinder and is arranged on the surface area of the printing cylinder, • a second rail that essentially extends parallel to the rotational axis of the printing cylinder, is arranged on the surface area of the printing cylinder and composed of at least two partial rails, wherein • the first rail and the second rail respectively have at least one undercut for accommodating the at least one plate or the at least one printing plate in a form-fitting manner, and wherein • the at least one first rail and the at least one second rail are spaced apart from one another by a variable distance in the circumferential direction of the printing cylinder, as well as • two tensioning units that are spaced apart from one another in the direction of the rotational axis of the printing cylinder and respectively at least comprise a slide that essentially can be moved in the circumferential direction of the printing cylinder, a drive that is operatively connected to the at least one slide and a partial rail that is arranged on the slide and forms the second rail, wherein at least one lock is arranged opposite of at least one partial rail of the at least one second rail, and wherein the at least one lock alternately has an open arrangement and a closed arrangement with respect to the at least one associated partial rail and forms a closable receptacle together with the at least one associated second partial rail, characterized in that the at least one lock is formed by a lever that has two limbs (61, 62) and is rotatable about an axis, wherein the rotational axis essentially extends essentially radially to the printing cylinder and the two limbs (61, 62) of the lever jointly define a plane, and wherein said plane essentially is aligned perpendicular to the rotational axis of the lock. • a first rail that essentially extends parallel to the rotational axis of the printing cylinder and is arranged on the surface area of the printing cylinder, • a second rail that essentially extends parallel to the rotational axis of the printing cylinder, is arranged on the surface area of the printing cylinder and composed of at least two partial rails, wherein • the first rail and the second rail respectively have at least one undercut for accommodating the at least one plate or the at least one printing plate in a form-fitting manner, and wherein • the at least one first rail and the at least one second rail are spaced apart from one another by a variable distance in the circumferential direction of the printing cylinder, as well as • two tensioning units that are spaced apart from one another in the direction of the rotational axis of the printing cylinder and respectively at least comprise a slide that essentially can be moved in the circumferential direction of the printing cylinder, a drive that is operatively connected to the at least one slide and a partial rail that is arranged on the slide and forms the second rail, wherein at least one lock is arranged opposite of at least one partial rail of the at least one second rail, and wherein the at least one lock alternately has an open arrangement and a closed arrangement with respect to the at least one associated partial rail and forms a closable receptacle together with the at least one associated second partial rail, characterized in that the at least one lock is formed by a lever that has two limbs (61, 62) and is rotatable about an axis, wherein the rotational axis essentially extends essentially radially to the printing cylinder and the two limbs (61, 62) of the lever jointly define a plane, and wherein said plane essentially is aligned perpendicular to the rotational axis of the lock.