1.25 and 2 inch (M48) Filter Rings with Retainers
These are empty filter rings in two sizes popular for astronomy.
Black anodized aluminum, male threads on one side and female
threads on the other. The retainer ring threads in to hold
the glass. Can be used as spacers, and can also be used as
99.9999% transmission, zero reflection, extremely wide band
The 1.25" (1-1/8" 40 tpi threads) size holds 1.10" diameter
glass up to 1/8" thick. 1.22" outside diameter, 0.45" overall
thickness, 0.305" extension thickness.
The 2" or M48 size 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, 0.3"
Prices include shipping in the USA!