TECHSPEC® C, S, and T-Mount Extension Tubes add extension length to an optical system while blocking external light and debris from entering the system. Extension tubes are available with C, S, or T-Mount threading, allowing them to be integrated into a wide range of systems and applications. Their black anodized aluminum construction, combined with a threaded inner diameter, ensures that stray light is reduced within the system. TECHSPEC C, S, and T-Mount Extension Tubes feature different lengths that can be combined to create the exact extension length needed for a specific application. The actual tube length is longer than the extension length due to the male threaded portion.