Wilson special tools are required for mounting the pickups correctly. The 4.90 mm precision drill and the special handmade 4.99 mm reamer are required to obtain the maximum output of sound from the 5.01 mm piezo pickups. A wooden stick is required to help removing the pickups from the bridge. Please note: Special tools are included when purchasing type K pickups. Set contents: Drill bit and special reamer tool, to drill the holes, as well as a wooden stick for removing the pickups from the bridge correctly.