Cal Test Electronics CT4406 4mm Sheathed Banana Jacks operate up to 5kV when used in non-category environments with transient overvoltages up to 2kV. These banana jacks should be used only with the CT3018 or CT3020 long-reach high-voltage test leads. The CT4406 banana jacks are 1000V CAT IV rated and offer an M3 threaded connection hole. The CT4406 banana jacks fit into plastic and metal panels fixed with a 14.5mm hex panel nut and are available in black and red color options.