The LBTEK 2-inch stackable slotted lens tube features side slots, enabling quick and easy assembly of complex optical components while allowing adjustment of optical elements without disassembling the setup. Multiple retaining rings can be used to mount several optical elements within a single lens tube. First, screw the first retaining ring to the required depth, place the optical element, and then secure it with the second retaining ring. The side slots allow manual adjustment of optical elements without requiring a retaining ring wrench. The lens tube comes with a rotatable sliding cover that can conceal the slots, preventing stray light from entering the system while maintaining optical cleanliness. Each lens tube includes two retaining rings.

These SM2 lens tubes are machined to the required exact length for positioning Microscopy Cameras with standard C-mount interfaces at the image plane of the Tube Lenses.

Each lens tube has an SM2 （2.035"-40） threaded hole for mounting Ø2 inches（Ø50.8 mm） Optical Components, and includes an SM2R retaining ring.

LBTEK extension tubes are used to extend the spacing between Optical Components in Optical Systems with long Focal Length  Lens, and can secure Optical Components with a diameter of Ø50.8 mm. Each extension tube is supplied with one SM2R retaining ring. Both ends of the extension tube are threaded, allowing direct connection with SM2 Lens tubes for free combination in the length direction. Compared with standard SM2 Lens tubes, its tube wall is thickened, providing higher structural rigidity under long-distance support conditions and reducing optical axis deviation caused by tube deflection or deformation.