A water dilutable UV-curable polyurethane containing alkylene oxide groups, the polyurethane being obtained from components comprising at least: 1 to 25 wt. In particular, the mounting structure comprises a conductive material and is electrically connected to the protected electrical device. The driver circuit allows the aggregate forward voltage drop of all the LEDs connected in series to approach the rectified input voltage to efficiently utilize the AC power from the mains. As the magnetically tagged particles are held by the spin-valve elements, application of an auxiliary magnetic field can be used to apply tension or torsion to the held particles or to move, e.