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Filter Thread Eyepiece Barrel Extensions

For eyepieces that need to be extended out a bit to reach focus, a
common problem with Newtonians. These extensions screw into the
eyepiece barrel filter threads and extend the barrel. The extensions
are also threaded for filters. Machined from aluminum, anodized black.

Parfocalizing rings can be used as an insertion stop, sold separately.
Eyepiece and filter not included.

The #OIFR 1.25" (1-1/8" 40 tpi threads) Filter Cell provides a 0.30"
extension length. Holds 1.10" diameter glass up to 1/8" thick. 1.22"
outside diameter, 0.45" overall thickness.

The #TIFR 2" or M48 size Filter Cell provides a 0.3" extension length.
Holds 1.850" (47mm) diameter round glass up to 1/8" thick. ~1.996"
outside diameter, 10.5mm overall thickness. Female threads are
6mm deep, male threads are 2.6mm deep.

Click on images to enlarge.
#EPE2 2" version shown with a filter installed:

$24.00 - #EPE2 - Filter Thread 2" Eyepiece Barrel Extension, 1" Long

$00.00 - #TIFR - No Longer Available - 2" (M48) Filter Ring with Retainer

$24.00 - #EPE1 - Filter Thread 1.25" Eyepiece Barrel Extension, 1" Long

$22.00 - #EPE5 - Filter Thread 1.25" Eyepiece Barrel Extension, 1/2" Long

$00.00 - #OIFR - 1.25" Filter Cell / Filter Thread Eyepiece Barrel Extension, 0.305" Long

$18.00 - #PFR1 - Two parfocal rings for 1-1/4" barrels

$24.00 - #PFR2 - Two parfocal rings for 2" barrels

Price includes shipping in the USA!

Ordering Information

Parfocalizing Rings are here!

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