Blue Fireball Empty 1.25" Filter Cell with Retaining Ring # S-1F

Our Price: $8.95
  • Buy 3 for $8.25 each and save 8%
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In Stock (10+ Available)
Ships by Next Business Day
Our Product ID: PAAR-BF-S-1F
Manufacturer SKU: S-1F
Item Can Ship: Worldwide
Blue Fireball Empty 1.25" Filter Cell with Retaining Ring # S-1F

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Product Details


  • 1.25" empty filter cell for astronomy filters
  • Great replacement for old, worn filter cells or those with threading issues
  • Will accept filter substrates between 26.5mm and 27.7mm in diameter. Please measure your glass filter before purchasing this item to ensure fit.
  • Can also be used as a 1.25" 7.7mm long spacer ring


  • Precision machined from aluminum and black anodized
  • Has standard 1.25" filter threads (male on one side and female on the other)
  • Threads into any standard 1.25" eyepiece, barlow, diagonal, camera nosepiece, and accessories with compatible female thread
  • Includes retaining ring with two notches 180-degrees apart to hold glass filter substrate within filter cell
  • Made in Taiwan


  • Total length of filter cell = 0.44" (11.2mm)
  • Extension provided = 0.30" (7.7mm)
  • Length of external male thread = 0.14" (3.5mm) including unthreaded undercut; 0.1" (2.5mm) excluding undercut
  • Thread specification (external thread) = M28.5x0.6 male
  • Length of internal female thread = 0.24" (6.1mm)
  • Thread specification (internal thread) = M28.5x0.6 female
  • Maximum outside diameter = 1.23" (31.3mm)
  • Retaining ring length = 0.1" (2.5mm)
  • Will accept unmounted filters between 26.5mm and 27.7mm in diameter and up to 3.5mm thick

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