GSO 2″/2″ extension tube - 35mm
Sometimes a standard focuser simply does not offer enough travel. Whether you are working with a Newtonian reflector that has a short focuser draw tube, or you want to use a refractor without a diagonal, the GSO 2″/2″ extension tube with 35mm optical length reliably solves the problem of reaching the correct focus position. It is a simple but enormously useful accessory that even experienced observers occasionally cannot do without.
When do you need a focuser extension tube?
This extension tube finds use in a wide range of situations:
- Newtonian reflectors with short focuser travel - typically compact or fast Newtonians - often make it impossible to rack the eyepiece in far enough to reach the focal plane. Adding this tube gives you an extra 35mm of optical length, making focus comfortable and fully achievable.
- With refractors, using the telescope without a dielectric prism or mirror diagonal is a common choice for photography or specific visual observations. Without extending the focuser travel, focus would simply be out of reach.
2″ to 2″ connection - universal compatibility
The tube is designed as a two-sided 2″ connection - one end slides into the telescope focuser, and the other end accepts an eyepiece or other accessories in the standard 2″ format. This makes it fully compatible with a wide range of eyepieces, cameras, filter drawers and other accessories you may already have in your kit.
Quality GSO build at a reasonable price
GSO accessories have long been popular among astronomers for their solid construction and good value. The tube is made from metal, and the interior surface is matte-finished to prevent unwanted reflections that could negatively affect image contrast. The threaded or screw-type fastening ensures a firm and secure connection with no risk of accessories shifting during observation.
A small accessory with lasting value
If you are looking for a reliable and affordable way to expand the versatility of your telescope, the 35mm 2″ extension tube is exactly the kind of accessory you buy once and use for years - with different telescopes, different eyepieces, and for both visual and photographic observing.
Key specifications
| Parameter |
Value |
| Barrel size (input) |
2″ |
| Barrel size (output) |
2″ |
| Optical length |
35mm |
| Material |
Metal |
| Interior finish |
Matte anti-reflection |
| Fastening |
Threaded / screw lock |
| Brand |
GSO |
