Like the 510 'Diamond logo' pickups that preceded them, the 511 pickups are mounted via four grub screws, two each on the top and bottom edges of the plastic surround. These can be loosened to allow the pickups to be raised or lowered and then simply retightened. Note that the bridge pickup surround is taller than the neck - both are held in place by two screws accessible once the pickup itself is removed.
The nickel plated covers have no logo or branding, just six fixed (staple) pole pieces and six adjustable (screw head) pole pieces, in two columns. Removing the pickups and their surrounds is a simple matter, revealing a small hole in the guitar's top through which the pickup leads enter the guitars body and volume and tone controls. There is no route (cutout) in the top of Hofner guitars to accomodate these pickups.
The pickup was described as follows in the 1965/1966 Selmer catalogue
Another Hofner innovation is the wonderful "Nova-Sonic" pick-up included on all ‘66 models. As with its famous predecessor, "Nova-Sonic" completely eliminates the overpowering second string tendency found in conventional pick-ups, but in addition offers other important advantages. It is built on the double pole, double coil principal and has one set of magnet heads exposed. This means that you get a higher gain than normal arrangements and obtain full total value. Like all Hofner developments, "Nova-Sonic" has been meticulously tested by experts so that no adjustment is necessary by the player.
"Nova-Sonic" is a Hofner exclusive and is available as a separate item.
List of Hofner guitar pickups