All astrophotography equipment requires critical spacing in relation to the astronomical imaging camera so that proper focus can be achieved. Without correct spacing for your gear, your astrophotographs will most likely be plagued by fuzzy, unfocused stars and exhibit lackluster resolution. Finding the means to obtain just the right amount of spacing can be difficult to say the least. Our helpful T-thread Spacer Ring Kit includes a 5mm, 10mm, and 25mm spacer ring with male T-threads on one side, and female T-threads on the other, so you can mix and match them to achieve ideal spacing depending on the specific needs of your particular astrophotography setup. Each spacer ring features an easy-grip knurled exterior, and a glare-reducing threaded interior to maximize contrast. The black anodized aluminum spacer rings can also be used as extension tubes. Any astrophotographer who uses off-axis guiders, focal reducers, coma correctors, field flatteners, adaptive optics guiders, or other imaging accessories needs the versatile and affordable Orion T-thread Spacer Ring Kit in their accessory case. Don't leave home without it!