Base Lab Tools offers industry standard lens tubes with internal 0.535-40, 1.035-40, and 1.535-40 threads for pre-mounting optics. These lens tubes include a retaining ring for securing Ø0.5in, Ø1in, and Ø2in optics within the tube. There are also a wide variety of adapters available for mounting other size optics, fiber and more. Each lens tube has 0.12in of external thread so they can be attached together or mounted in other internally threaded mounts. These lens tubes are made of RoHS-compliant, corrosion-resistant, black anodized, aluminum alloy.