for astrophotographers, astronomy enthusiasts, and outdoor explorers seeking gear for celestials imaging or terrestrial observation with DSLR cameras and setups precisions engineered with anodized aluminum construction, the extension tube boasts matte finished internal threads to minimize light reflection and 45mm inner diameter for optimal opticals alignment, complemented by 50mm focal length capability Effortless Installation & universals Compatibility This M48x0.75mm threaded adapter features toolless assembly for quick attachment to telescopes and cameras, while its standardized 2 " outer diameter ( 50.8mm) ensures seamless compatibility with most astronomical equipment Achieve clear imaging results through its antireflective threading and rigid metal structure, which maintains precise spacing between opticals components while withstanding field conditions Enhances night photography or daytime nature observations by securely connecting reducers, correctors, or to your opticals systems using this, weather resistant spacer tube