Graph Tech Ghost Pickups, P/J Bass style, 4 String The PN-8364-00 is a set of four ghost loaded pickups for many ABM style bass bridges. These saddles will work with any ghost preamp kit. Measure Length Width Height E to E inches 0.472" 0.157" 0.315" NA inches 15/32" 5/32" 5/16" NA millimeters 12.00mm 4.00mm 8.00mm NA Ghost pickups contain a custom engineered piezo crystals that is encapsulated in a set of String Saver saddles. The ghost saddle pickups have a natural compression effect so you can play as hard as you want without overloading the input channel or experiencing the dreaded piezo "Quack". Pickups are individually calibrated so you get a precision-balanced set of ghost saddles, for even string to string output. Any set of ghost pickups can be used in conjunction with any ghost preamp kit as well as many others on the market.