Replacement humbucker covers.
The material of the cover will affect your pickup tone. Nickel silver will cause a subtle decrease in treble response, brass will cause a far more significant decrease, Brass is perfect for taming bright pickups.
Slide on top of your humbucker and solder onto the baseplate.
See our printable PDF to check for size - https://drive.google.com/open?id=1gf1nNpbufPiGU_ECMfGvkjccIbouXM6n (50mm)