High performance valve stem seal for all 6mm valves made of Viton. These valve stem seals offer the following advantages: High temperature resistance Improved sliding properties Longer life Can be used on both intake and exhaust valves. When using new valves, the guides must also be renewed! Price for 20 stem seals. For 20 Valves. Manufacturer Information about the manufacturer BAR-TEK BAR-TEK Motorsport GmbH Im Rauschen Auel 3, 51491 Overath-Brombach, Germany info@bar-tek.com