Antares Variable M48 Camera Adapter Product Highlights: Antares Variable M48 Camera Adapter Male-to-Female Adapter for M48 Threads Provides Spacing of 31 mm up to 49 mm Used to set a precision back focus for a camera Accepts standard 2" threaded filters The Antares TEXT48 Variable M48 Camera Adapter is a device which allows you to set a desired precise back focus distance for doing astro-imaging with your camera and telescope. Astro-imaging using intermediary lens systems can require a precision back focus to the image plane so as to obtain the best color and eliminate any field curvature. With this Male-to-Female M48 adapter you can have a separation range of 31 mm - 49 mm. Lets you set up your camera for the optimal imaging situation. Comes with a locking ring and accepts 2" filters. Specifications: Manufacturer: Antares Antares Model No: TEXT48 Function: Variable Spacing M48 Camera Adapter Thread Size: M48x0.75 mm threads Mates To: male on one end; female on other end