Feature:1. M42x0.75mm Thread: M42x0.75mm thread, make sure the connection is firm and tight, and will not fall off easily.2. Matting Treatment: The inner wall of the aluminum alloy adapter rings is subjected to matting treatment to prevent the radiation from affecting the imaging.3. Male to Male: M42 to M42 rings adapter, male to male, easy to install and won't cost you too much time.4. Aluminum Alloy: Aluminum alloy material, accuracy craftsmanship, durable and corrosion resistant, can be used for a long time.5. Small and Portable: The Telescope adapter is flexible to use, small and portable, and can be easily carried and used even when going out.Specification:Item Type: M42 Male to Male AdapterMaterial: Aluminum AlloyThread Specification: T2 Thread (M42x0.75mm)Thread Depth: Approx. 3mm / 0.12inFlange Distance: Approx. 2mm / 0.08inClear Hole Diameter: Approx. 38mm / 1.5in.Package List:1 xM42 Male to Male Adapter