This item is a 1piece guide shaft seat that also serves as an optical axis bracket. It combines a round seat with a flat flange to provide a compact, stable mounting point for guide shafts and optical axis components. The base has a circular footprint of 40 mm, and the unit supports multiple installation sizes for versatile use. Key benefits Stable alignment: designed to hold guide shafts and optical axis components securely, reducing wobble and improving repeatable positioning. Versatile mounting: compatible with a wide range of installation sizes, enabling use across different setups without needing multiple adapters. Compact footprint: round seat with a flat flange fits into tight spaces while providing reliable support for precision assemblies. Simple integration: straightforward mounting and alignment so you can install quickly in existing optical or mechanical assemblies. Key attributes Functionality: guide shaft seat, optical axis bracket, round seat, flat flange in a single unified part. Compatibility: installation sizes 8, 10, 12, 15, 16, 20, 25, 30, 35, 40, 50 (40 mm) and a 40 mm circular base. Size: circular base diameter is 40 mm. Material: not specified in the product title. Finish: not specified in the product title. Quantity: 1 piece. Specifications and compatibility notes Includes: 1 piece as listed in the product title. Application scope: suitable for aligning and mounting guide shafts and optical axis components in precision assemblies. The exact material and finish are not provided in the title; intended usage should consider standard compatibility with typical guide shaft and optical axis hardware. Two to three use cases Optical alignment in a compact laser setup: use the round seat and flat flange to mount an optical axis bracket, achieving precise, repeatable alignment in a small lab bench space. DIY CNC or 3D printer rail support: install as a mounting base for a guide shaft to improve straightness and stability of a linear axis. Microscope or machine vision fixture: employ the 40 mm circular base to secure a guide shaft seat for stable positioning of imaging optics or sensors. Packaging 1 piece per unit.