Feature:1. Seamless Connection: This telescope adapter ring features seamless connection, M42 and M48 fittings can be connected together.2. 0.75mm Thread: This M42 to M48 coupling ring adapter possesses M42x0.75mm external thread and M48x0.75mm internal thread.3. Aluminium Alloy: This M42 to M48 ring adapter is made of aluminium alloy material, sturdy and durable.4. Easy Installation: This telescope adapter ring can be easily installed, very flexible and convenient to use.5. Extinction Treatment: The inner wall of this telescope lens filter ring adapter adopts extinction treatment, avoid radiation affecting the image.Specification:Item Type: Telescope Adapter RingMaterial: Aluminium AlloyInternal Thread Specification: M48 x 0.75mmExternal Thread Specifications: M42 x 0.75mm (Commonly Known As T2 Thread)Thread Depth: 3mmFlange Distance: 4mmTotal Length: 7mmDiameter of Inner Hole: 39mmOuter Frame Diameter: 50.7mm0.1mm.Package List:1 xTelescope Adapter Ring1 x Plastic Storage Box