All the plugs are made of durable material for long time use. Banana sockets suitable for 4mm banana plugs, spade terminals or bare wire. They are great tools for using in the audio equipment, perfect for speaker, multimeter probes. Screw connector fitting, secure the wire in the adapter without the need of soldering, easy to use. Features - Color: Black and red. - Material: Nylon and copper. - Size: 5.00 x 0.50 x 0.50cm/ 1.97 x 0.20 x 0.20 inch. - Soldering seal protection shrouded banana plug connector multimeter test leads banana plug adapter. - The materials selected for our products are nylon brass nickel plate, durable and can be used for a long time. - Can connect all standard 4mm banana plug adapter ( shrouded , non shrouded , retractable plug ). - Easily dealing with currents and preventing leakage issues from occurring. - The nylon wire inside will make it withstand bending thousands of times without breaking or fraying.