From Fender:
The sound of Fender’s flagship instruments. Fender Ultra Noiseless pickups are the pinnacle in stacked single-coil design, crafted with new winding techniques for livelier and more expansive tone. Alnico 5 magnets with polysol wire deliver a vintage voice with classic bell-like chime and no unwanted hum.
Ultra Noiseless Hot Strat pickups are overwound for more output and will hold up with high levels of distortion with no hum.