PRODUCT NAME --- Stackable Banana Plug Connectors; Body materials: brass; Spring Materials: Beryllium Copper; Surface materials: nickel plated; Color: Black+Red PRODUCT NAME --- Stackable Banana Plug Connectors; Body materials: brass; Spring Materials: Beryllium Copper; Surface materials: nickel plated; Color: Black + Red 14 AWG WIRE RECOMMENDED --- Stackable banana plug connectors support 14 AWG wire HIGH QUALITY MATERIAL --- Made of high quality material quality, the main body is made of brass, the spring is nickel-plated on the surface of beryllium copper, and the shell is plastic. MAXIMUM CABLE DIAMETER 4MM --- The maximum cable diameter is 4mm in connection for welding ELECTRICAL TEST --- This 4mm stackable banana connector can be used for electrical test