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Extension tube provides extra focuser "back travel" often needed for short-range terrestrial viewing through a telescope, or for astrophotographic applications.
Fits in 2" telescope focusers, and accepts 2" eyepieces or accessories. Threaded for use with standand 2-Inch astrophotography filters.
Features two locking thumbscrews to secure any inserted astronomy accessory, with a brass compression insh to prevent the marring of your telescope accessories.
With this simple and useful device, you can extend the focal length of your telescope 80mm or a little more. Machined of high quality aluminum and anodized black, resistant for long time use.
david
2025-08-31 13:53:15
Bought this because 2"eyepieces bring focal length right to bottom4 mm on my Orion 8" reflector that was to tight, it works out well because am changing focal tube on my Meade 102mm infinity and the 2 speed I am installing will definitely make that short with 2" eyepieces.
Jaime Z.
2025-08-27 21:02:56
Durable and very well constructed, it holds my elements very firmly. Convenient price and availability compared to branded items.
Stephen W. Ramsden
2025-08-08 11:09:01
it’s everything you would expect from a decent quality astronomy accessory. I recommend it.
Craig Rush
2025-08-01 12:43:49
Good quality piece. No complaints.
jay
2025-07-23 19:16:02
Had to get an extension for my 4 inch refractor when I upgraded the focuser to a GSO 2-Speed. This is a fantastic value! Has good flat black inside for anti-reflection coating, and compression rings to hold the eyepiece. Really nice at this price point and it holds even the heaviest eyepieces securely.
Gypsy
2025-06-28 15:01:13
Nice solid construction, works well, hefty weight to it though, but makes sense, its made with quality materials.
Dan B.
2025-04-15 19:46:55
There's something quite pleasing about an over-engineered product. The eyepieces I'm attaching this to are made of plastic, yet here's this tube, made of machined aluminum seems like it could be aircraft grade.Fits well, secures easily and tightly, and does what I need it to.
Amy H.
2025-03-14 12:33:47
The Alstar 2-Inch Telescope Eyepiece Extension Tube Adapter has been a fantastic addition to my astrophotography toolkit! This extension tube provides just the right amount of extra focuser travel I need, especially for short-range terrestrial viewing and capturing stunning celestial images.The build quality is excellent; it’s machined from high-quality aluminum and has a sleek anodized black finish that not only looks great but also promises durability for long-term use. The two locking thumbscrews make it easy to secure any inserted eyepieces or accessories, and the brass compression ring is a thoughtful touch that prevents any marring of my gear.Fitting it into my 2-inch telescope focuser was a breeze, and it easily accepts 2-inch eyepieces or other accessories. I also appreciate the threaded design for standard 2-inch astrophotography filters, which adds versatility for my astrophotography sessions.Overall, this extension tube has significantly improved my viewing experience and has been instrumental in my astrophotography endeavors. If you're looking to extend the focal length of your telescope, I highly recommend the Alstar extension tube for its quality, ease of use, and effectiveness!
Mr H
2025-02-19 11:26:16
This is a good quality extension tube. Very well made, giving the feel of a high quality product. The only thing that doesn't work for me is that the internal sleeve is too close to the top of the tube, where the eyepiece is inserted. It's fine for most 2" eyepieces, however with my TeleVue 2x Powermate, the barrel is long enough that it doesn't sit flush with the top of the extension tube, as the internal sleeve inside the tube isn't far enough down to allow the Powermate to be insert fully. A minor point but worth mentioning.It's still great value for money product though and I'd highly recommend it for normal eyepieces.
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