Schrader Duncan Limited supplies Semi Flexible Spring Lined Bundy Tubing Extension. Schrader Duncan Limited is an ISO 9001 certified company. The Semi Flexible Spring Lined Bundy Tubing Extension is ruggedly built for wheel conditions where a light weight, rigid, yet hand-bendable-to-shape type accessory is desired. The Spring Lined Bundy Tubing Extension is available with spring lined braided cover for protection and a sealing core at the extension mouth.