Celestron 93618 M42 Spacer Kit Includes 7.5mm, 12mm and 30mm Rings to Adjust Back Focus Between Camera Telescope, Black

BACK-FOCUS DISTANCE: Adjusts back-focus between your camera and telescope for the best astroimaging results. If the back-focus distance your camera consumes is not exact, the performance at the corners of full frame imaging sensors will suffer—stars will appear elongated and not as pinpoints. SPACER RINGS: Kit includes 3 spacer rings of different lengths (7.5mm, 12mm, 30mm) to achieve the proper back-focus distance with Celestron optical tubes and T-thread camera adapters. THREADING: Threads to your T-Ring and T-Adapter with standard male and female T-Threads. Each spacer ring has a knurled surface, providing a great gripping surface for threading/unthreading. MATERIALS: The M42 Spacer Rings are black anodized machined aluminium. The internal surfaces are blackened and glare-threaded to provide the highest contrast. UNBEATABLE WARRANTY AND CUSTOMER SUPPORT: Buy with confidence from the world’s #1 telescope brand, based in California since 1960. You’ll also receive a 2-year warranty