Faq II: Equipment & Maintenance:

2.11 Body Wires

     The primary question with foil and sabre body wires is bayonet
     vs. two-prong.  They are equally functional; the primary
     difference is in cost and maintenance.  Two-prong is a simpler
     design, and usually less expensive, but also has a reputation for
     being less reliable (depending on the brand).  Naturally choice
     of body wire also determines the choice of weapon socket (or vice
     versa).  One of the primary considerations in deciding which
     format to go with should be the prevalent format in your club or
     region.  Going with the local favourite will make it easier to
     borrow weapons or wires when yours fails.

     Epee body wires are all of the same basic 3-prong design.  Some
     (French) deisgns have metal sheaths on the prongs that can
     accumulate grime underneath them over the years.  If not cleaned,
     the dirt can break the circuit at inopportune times.