SVBONY Extension Tube M42x0.75 on Both Sides Length T2 Extension Tube Kit Length 5mm 10mm 15mm 20mm

Great quality and value. Unfortunately, the 5 mm and the 10mm are stuck together. I tried filter wrenches to separate them, which didn't work, so I wrapped them in tape and used pipe wrenches, but that still didn’t work. I will assemble everything tomorrow that I purchased it for, and we will see if I need them separated. I also bought the Variable Extension Tube, so I hope to use it to achieve the precise length I need. Just an update SVBONY reached out to me offering a refund on this product. I was very impressed. I planned to order another set and a few other items they make because the quality and value are very good, and that gesture made me a definite SVBONY customer.

These extension tubes screw right onto the celestron T adapter that fits onto the .7 focal reducer. Nicely machined, very happy now that I've achieved 105 mm of backfocus. Great value. Also my new ZWO ASI 294 screwed right onto the T adapter. Edit...... Dont let them get stuck together, using channel locks to get them apart destroys them. Store them apart. You may find you need to paint them inside with a flat black paint. They seem to be glossy and I have had an issue with reflection. A quick spray fixed that.

Seems well built.

The "features" list of the template have no applicability here! Front and Rear Threads do not align properly The aluminum rings are well made and anodized. The screw threads are clean and smooth. There are two down-sides: * The insides of the rings are grooved to reduce reflections, but still too reflective. I may spray paint with matte black. * The threads are not "synchronized"; i.e. the orientation of a camera is not preserved if a ring is added. This requires a major adjustment of something else. The comments are same as those I made for the 8, 25, and 45 mm set of SVBony tubes. This set (5, 10, 15, 20 mm) is more convenient, but spans a narrower range.

On too many occasions, I've needed one or more of these extensions to reach proper backfocus for astrophotography. This set of extension rings is a small investment that will easily pay off over time.

These added just the right extension for my Sony NEX6 on a Celestron Nexstar 127slt telescope to be able to focus the camera. Inexpensive solution to a focusing problem. The picture is of the full moon - horribly bright so it makes it hard to see details on the moon's surface. You may want to scuff the inside to avoid stray light reflections. I didn't have that problem, though.

I needed the 10mm extension but had to buy the whole kit, which was no problem but when I got them, the 5mm and 10mm extension were screwed together so tight that I couldn't get them apart. I tried to use channel locks but, in the end, they got damaged trying to get them apart. There was absolutely no way to salvage them. I really needed them the day they arrived, but I was unable to use them. *UPDATE* Since I wrote the first review, SVBONY has reached out to me several time, which I appreciate as I use several of their products. The 2nd set that I received seems to work just fine as I did a mock setup to test everything. Still disappointed that the first set made it through QA like that but in SVBONY's defense it could have been a one-off event. I will give these a field test whenever it stops raining here in Atlanta and change my review as warranted.

They work perfectly and priced more than fairly. No regrets whatsoever w/ the purchase. Fast delivery.