Seymour Duncan SHPR-1n P-Rails Humbucking Pickup (Neck/Black) w/ Strings and Cable P-Rails are best used in a matched neck and bridge set P-Rails can be used in any guitar set up for a traditional humbucker or Trembucker Normally, in humbucking mode, P-Rails are wired in series, for a high-output sound that works great for classic rock and heavier tones.