A universal double-jointed coupling for railway vehicles with two joint levels comprises two coupling joints which are interconnected via a shaft that is surrounded by a hollow pinion shaft in order to transmit torque by means of said hollow pinion shaft. The light-emitting device, in an aspect, is coupled to a controller, a light-emitting diode array, and a power supply, wherein the power supply can be an AC power source or an unregulated DC power source. The site of concern is constantly maintained on the same scale to reduce the chance of inducing errors. Multiple power generating methods are disclosed, as is a Hybrid type engine utilizing at least two of the multiple methods in a plurality of cylinders. Traversing the ribs 72, 76 of the carcass or the tread belt are fluid or gas venting subsurface passages 80, 82 that are open to one or more groove 74, 78. The abrasive material is allowed to cure to create an abrasive pad having abrasive dots.