The Cal Test CT4231 binding post is perfect for electronic and electrical projects large and small. The versatile threaded binding cap accommodates spade lugs, bare wires, and 2 mm pin tips through the cross-hole. The co-axial banana jack accepts standard, retractile sheath, and fixed sheath 4 mm banana plugs. The binding post is front panel mounted with the same proven system as Cal Test’s 4 mm Sheathed Banana Jacks, 12 mm round or ‘double-D’ hole, to ensure maximum stability and retention. A compact round panel nut makes for easy assembly. For easy wiring, the binding post features an M4 threaded stud for ring or spade lug connection - M4 nut, flat washer, and lock washer are included. Additionally, the threaded stud features a turret end for solder connection.