These premium Woo Audio Teflon 4-pin tube sockets are a fantastic upgrade over standard ceramic tube sockets. Each 4 pin socket is machined from Teflon. Teflon is a superior material with great isolation and temperature endurance making it a premium tube socket suitable for high end audio and other critical applications. The unique socket pin design holds each tube pin on all sides. This contact design contacts more area of the tube pin, which greatly increases connectivity and gripping. The pins and contacts in this 4-pin teflon socket are gold-plated over oxygen free copper.