The rings that your humbucker pickups install into.
Available in arched top or flat version
.
Neck version is 5mm tall, Bridge is 7mm.
Compatible screws available under the screw section.
See our printable PDF to check for size - https://drive.google.com/open?id=1-9Q2z4H8f7P2t1-b1-S8tCxA249o7CdO