An electrical contact unit or LED unit for electrical control circuits of industrial machines or plants, wherein an electric circuit comprises ono or more wiring terminals, which unit comprises: - a casing housing thereinside at least one pair of electrical contacts and having a housing defining a longitudinal extension axis; - an actuator or a LED circuit selectively housed into said casing and electrically connected with said electric contact; - at least one pair of clamps for wiring said electrical contacts and the connection thereof to an electrical circuit, said wiring clamps being accessible through respective side holes of said casing for the insertion of the wiring cable terminals and wherein each of said clamps comprises an elastic lamella having one or more contrast arms adapted to hold the wiring terminals on said electric contacts; wherein each of said clamps comprises at least one push-button slidably inserted into said casing and adapted to be brought into contact with a respective of said elastic lamellae to promote the elastic flexion of said contrast arms and move them away from the respective of said electrical contacts to allow the insertion or removal of the corresponding wiring terminal; characterized in that each elastic lamella is coupled to the respective electric contact, each of said electrical contacts comprising contact surfaces for respective wiring terminals on which said contrast arms of the respective elastic lamella operates, said elastic lamellae further comprising a support plate integral with the respective contrast arms and on which said contact surfaces of the respective of said electrical contacts lie; and in that the push-buttons of each of said clamps are slidable in said casing along a respective direction parallel to said longitudinal extension axis for transmitting to a corresponding one of said elastic lamellae an also substantially axial force and in that each of said elastic lamellae comprises at least one pair of contrast arms staggered with each other and having a free end adapted to rest on a corresponding of said electrical contacts. - a casing housing thereinside at least one pair of electrical contacts and having a housing defining a longitudinal extension axis; - an actuator or a LED circuit selectively housed into said casing and electrically connected with said electric contact; - at least one pair of clamps for wiring said electrical contacts and the connection thereof to an electrical circuit, said wiring clamps being accessible through respective side holes of said casing for the insertion of the wiring cable terminals and wherein each of said clamps comprises an elastic lamella having one or more contrast arms adapted to hold the wiring terminals on said electric contacts; wherein each of said clamps comprises at least one push-button slidably inserted into said casing and adapted to be brought into contact with a respective of said elastic lamellae to promote the elastic flexion of said contrast arms and move them away from the respective of said electrical contacts to allow the insertion or removal of the corresponding wiring terminal; characterized in that each elastic lamella is coupled to the respective electric contact, each of said electrical contacts comprising contact surfaces for respective wiring terminals on which said contrast arms of the respective elastic lamella operates, said elastic lamellae further comprising a support plate integral with the respective contrast arms and on which said contact surfaces of the respective of said electrical contacts lie; and in that the push-buttons of each of said clamps are slidable in said casing along a respective direction parallel to said longitudinal extension axis for transmitting to a corresponding one of said elastic lamellae an also substantially axial force and in that each of said elastic lamellae comprises at least one pair of contrast arms staggered with each other and having a free end adapted to rest on a corresponding of said electrical contacts.