A pair of decent safety wire pliers is a must if you're going to be doing it with any regularity. This is the 9-inch pair offered by Graham Tool Co and features reversible action handy for both left- and right-hand twists. The other item necessary is a spool of safety wire. Pictured is a 1lb spool of 0.032-inch military spec stainless steel safety wire. This conforms to the military MS-20995-C and government QQW432 specs. What does that mean? Basically it means that it's the highest quality safety wire available and meets the FAA, military, and the NTSB requirements for use in aircraft.