Blue Fireball 2" Twist Lock Self Centering Eyepiece Extension Tube with 35mm (1.38") Extension

Stock count is accurate & shown in real time.
- This item is out of stock.
- Sign up for back-in-stock alerts to be notified when this item becomes available (account login required).
- This item is out of stock.
- Sign up for back-in-stock alerts to be notified when this item becomes available (account login required).
Contiguous US / Lower 48:
Free shipping applies to orders over $50 using our chosen carrier/method. Faster paid options are available at checkout.
Alaska, Hawaii & US Territories:
Free shipping applies to many—but not all—products. Enter your ZIP code in cart or upon checkout to confirm options and costs.
International:
International orders do not qualify for free shipping. Shipping, duties, brokerage, tariffs, and taxes are the customer’s responsibility. Some items may be restricted due to export, size, or manufacturer limitations.
New, improved version of Blue Fireball's X-03 eyepiece extension tube - with twist-lock, self-centering mechanism!
This high-quality Blue Fireball extension tube can be inserted into any 2" telescope focuser to gain an additional 35mm (1.38") of back-focus travel. With this, eyepieces and accessories that you may not have been able to use because your telescope tube was too short are usable again!
Lack of sufficient back-focus travel is a common problem with many of today's fast f-ratio telescopes, especially if you have a low profile focuser or a short telescope tube that is optimized for binoviewer viewing. The 35mm extension tube alleviates this problem. This tube can also be used with 1.25" accessories with the use of commonly available 1.25"-2" adapters (sold separately).
With this adapter, you can forget about fumbling with thumbscrews in the dark. Just twist and lock the knurled twist lock ring at the top, and your 2" eyepiece or other accessory will be centered precisely. The helical centering mechanism is controlled by an inner polypropylene compression ring that will not mar your eyepieces. Its long length ensures that the adapter works well with smooth and recessed eyepiece barrels.
It also includes a large thumbscrew should you feel the need to provide added security for heavy items after you have tigthened the twist lock ring; however, use of this screw is optional and not required for regular use.
This practical and superb quality adapter is made from precision machined aluminum and is black anodized. The inside surface of this tube is black-matted to enhance contrast by reducing stray light reflections and is threaded to accept standard 2" telescope filters.
Specifications:
- Total length = 67.7mm (2.67")
- Extension provided = 35mm (1.38")
- Weight = 3.3oz (94g)
- Compression band depth (from top edge) = 16.2mm (0.64")
- Compression band length = Approx. 16mm (0.63)
- Maximum diameter = 62mm (2.44")
Manufacturer part number: X-07
Other Information
- Country of Manufacture: Taiwan
New, improved version of Blue Fireball's X-03 eyepiece extension tube - with twist-lock, self-centering mechanism!
This high-quality Blue Fireball extension tube can be inserted into any 2" telescope focuser to gain an additional 35mm (1.38") of back-focus travel. With this, eyepieces and accessories that you may not have been able to use because your telescope tube was too short are usable again!
Lack of sufficient back-focus travel is a common problem with many of today's fast f-ratio telescopes, especially if you have a low profile focuser or a short telescope tube that is optimized for binoviewer viewing. The 35mm extension tube alleviates this problem. This tube can also be used with 1.25" accessories with the use of commonly available 1.25"-2" adapters (sold separately).
With this adapter, you can forget about fumbling with thumbscrews in the dark. Just twist and lock the knurled twist lock ring at the top, and your 2" eyepiece or other accessory will be centered precisely. The helical centering mechanism is controlled by an inner polypropylene compression ring that will not mar your eyepieces. Its long length ensures that the adapter works well with smooth and recessed eyepiece barrels.
It also includes a large thumbscrew should you feel the need to provide added security for heavy items after you have tigthened the twist lock ring; however, use of this screw is optional and not required for regular use.
This practical and superb quality adapter is made from precision machined aluminum and is black anodized. The inside surface of this tube is black-matted to enhance contrast by reducing stray light reflections and is threaded to accept standard 2" telescope filters.
Specifications:
- Total length = 67.7mm (2.67")
- Extension provided = 35mm (1.38")
- Weight = 3.3oz (94g)
- Compression band depth (from top edge) = 16.2mm (0.64")
- Compression band length = Approx. 16mm (0.63)
- Maximum diameter = 62mm (2.44")
Manufacturer part number: X-07
New, improved version of Blue Fireball's X-03 eyepiece extension tube - with twist-lock, self-centering mechanism!
This high-quality Blue Fireball extension tube can be inserted into any 2" telescope focuser to gain an additional 35mm (1.38") of back-focus travel. With this, eyepieces and accessories that you may not have been able to use because your telescope tube was too short are usable again!
Lack of sufficient back-focus travel is a common problem with many of today's fast f-ratio telescopes, especially if you have a low profile focuser or a short telescope tube that is optimized for binoviewer viewing. The 35mm extension tube alleviates this problem. This tube can also be used with 1.25" accessories with the use of commonly available 1.25"-2" adapters (sold separately).
With this adapter, you can forget about fumbling with thumbscrews in the dark. Just twist and lock the knurled twist lock ring at the top, and your 2" eyepiece or other accessory will be centered precisely. The helical centering mechanism is controlled by an inner polypropylene compression ring that will not mar your eyepieces. Its long length ensures that the adapter works well with smooth and recessed eyepiece barrels.
It also includes a large thumbscrew should you feel the need to provide added security for heavy items after you have tigthened the twist lock ring; however, use of this screw is optional and not required for regular use.
This practical and superb quality adapter is made from precision machined aluminum and is black anodized. The inside surface of this tube is black-matted to enhance contrast by reducing stray light reflections and is threaded to accept standard 2" telescope filters.
Specifications:
- Total length = 67.7mm (2.67")
- Extension provided = 35mm (1.38")
- Weight = 3.3oz (94g)
- Compression band depth (from top edge) = 16.2mm (0.64")
- Compression band length = Approx. 16mm (0.63)
- Maximum diameter = 62mm (2.44")
Manufacturer part number: X-07
Other Information
- Country of Manufacture: Taiwan

Blue Fireball 2" Twist Lock Self Centering Eyepiece Extension Tube with 35mm (1.38") Extension
