Celestron M42 Spacer Ring Kit

The Celestron M42 Spacer Ring Kit allows you to set the proper back-focus distance between your telescope and imaging rig. Getting the correct distance is critical for tack-sharp images—if it's not exactly correct, the corners of full frame imaging sensors will suffer and stars will appear elongated instead of as pinpoints. The kit comes with 7.5mm, 12mm, and 30mm rings with standard male and female T-threads that allow you to use them individually or stacked in any combination and then married to your camera-side T-ring and telescope-side T-adapter without the need for converter rings. Made of anodized aluminum and treated with a black anodized finish, the internal surfaces are blackened and threaded for glare reduction to provide improved image contrast.