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Please Note

Orion has made the difficult decision to close our warehouse facility in the Netherlands. With the continuing supply chain/logistics challenges and slowness in the economy we have found that it is not economically feasible to maintain operations in the UK and Europe.

We have therefore stopped taking orders on this website. We apologize for any inconvenience.

We will continue to have Orion dealers in Europe to meet the needs of Orion consumers. We will also continue to honor the 30-Day product return period as well as honoring the Orion warranty for purchases made in the UK and Europe.

Our US-based Customer Service Representatives are here to help. Contact them via email at support@telescope.com or in the United Kingdom, via phone at 0-800-041-8146 (Monday-Friday between the hours of 1300 and 2400 GMT).

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Orion Telescopes
Intermediate
Orion 1.25" Twist-Tight Dielectric Mirror Star Diagonal
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This product is no longer available for purchase.
  • 1.25", 90-degree mirror diagonal features sophisticated dielectric coatings with highly efficient 99% reflectivity for peak performance
  • Twist-tight clamping mechanism grips inserted eyepieces more securely than typical thumbscrew-equipped diagonals - without scratching!
  • Durable dielectric mirror coatings provide higher reflectivity for maximum brightness and contrast
  • Machined and anodized aluminum housing features machine-threaded glare baffles to eliminate glare for great performance
  • Nosepiece barrel threaded to accept 1.25" Orion filters


Learn more
Item #  40901u

The Orion 1.25" Twist-Tight Dielectric Mirror Star Diagonal gives the typical thumbscrew-equipped telescope diagonal a new twist -- literally! This innovative diagonal features a twist-tight clamping mechanism that securely grasps inserted 1.25" eyepieces and accessories with a simple clockwise twist of its red aluminum collar.

Unlike thumbscrew-equipped diagonals, the Orion Twist-Tight diagonal delivers equal inward pressure to precisely center eyepieces, camera nosepieces, and other equipment along the light path of the telescope with a more robust grip. What's more, since this diagonal doesn't use a thumbscrew, you don't have to worry about annoying scratches or gouges appearing on your treasured eyepieces, and there's no thumbscrew to lose in the dark! The easy-grip, knurled aluminum twist-tight collar is delightfully easy to adjust, even while wearing gloves during cold nights.

The Orion 1.25" Dielectric Twist-Tight Mirror Star Diagonal is built around a highly reflective mirror with sophisticated, lab-tested dielectric coatings providing 99% reflectivity. With such high reflectivity, this diagonal will help you obtain the brightest views possible through a refractor or Cassegrain telescope. The 1.25" Twist-Tight Diagonal's rugged anodized aluminum housing features machine-threaded internal baffles to ensure optimal contrast and also eliminate pesky internal reflections and glare. What's more, since dielectric coatings are more durable than enhanced aluminum coatings, you'll enjoy year after year of exceptional performance without degradation. 

The diagonal's 1.25" nosepiece barrel is conveniently threaded to accept like-sized filters so you can easily swap between different telescope eyepieces and other accessories without the hassle of re-attaching the filter each time. Protective caps are included to keep the diagonal free of dust when not in use.

Please note: diagonals are not recommended for use with Newtonian reflector telescopes.

Warranty

Limited Warranty against defects in materials or workmanship for one year from date of purchase. This warranty is for the benefit of the original retail purchaser only. For complete warranty details contact us at sales-eu@telescope.com

  • User level
    Intermediate
  • Design
    Kellner
  • Barrel size
    1.25"
  • Coatings
    Dielectric
  • Optical quality
    Diffraction limited
  • Filter threads
    Yes
  • Body material
    Aluminum
  • Compression ring
    Yes
  • 2"-1.25" adapter
    Sold separately
  • Weight (g)
    227g
  • Additional included accessories
  • Other features
  • Warranty
    One year

Orders received by 5pm UTC for in-stock items ship the next business day. When an item is not in-stock we will ship it as soon as it becomes available. Typically in-stock items will ship first and backordered items will follow as soon as they are available. You have the option in check out to request that your order ship complete, if you'd prefer.

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