Check the listing for details. HUBBELL HBLFRSBK Recpt,Black,Female,Threaded Stud,400 A 2XB54. Condition: New. Listed at 65.44 USD. Receptacle, Connection Orientation Straight, Current Rating 400 A, Gender Female, Housing Color Black, Housing Material Thermoplastic Elastomer, Maximum Wire Size 4/0 AWG, Minimum Wire Size 4 AWG, Phase Single, Voltage Rating 250V DC, 600V AC, Contact Material Brass, End Type Taper Nose, Flange Shape Square, NEMA Enclosure Rating 12, 3R, 4X, Standards ANSI/NFPA 70, cUL Listed, National Electric Code (NEC), UL Enclosure Types 3R, 4X, 12, UL Listed, Terminal Connection Type Threaded Stud The nonmetallic retaining screw on this single pole connector is designed to lock contacts in place so they don't move within the housing. A special screw thread also helps prevent installation 180 Degrees out of rotation and requires fewer turns, reducing the chance of a conductive screw being substituted.