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Orings

Orings are an excellent choice for telescope eyepieces and filters, camera lenses, and protecting the secondary mount gasket on SCT corrector plates and primary mirror baffle tubes. Orings can be used for nearly any mounted optic!

Orings can be used as a "dam" to avoid getting First Contact Polymer on your optic retaining ring. The retaining rings sometimes do not fit snug to the optic surface and the polymer, being a liquid, may possibly flow under the retaining ring and may not peel out, leaving polymer residue at the retaining ring edge. This also holds true for optics retained from the backside; the polymer can flow under the retaining lip. View our Oring Flow Control document to see photos and a description of how the process works.

Shipping: If only ordering orings we can ship via USPS for less than than FedEx. Let us know if you prefer USPS and we will adjust the shipping cost to a flat rate $6.00 before charging your card. We will also send you a revised invoice showing the adjusted total cost. Applies to the Lower 48 United States only.

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Orings - 3" to 3.875" (76.2 to 98.4mm) OD (Sold Individually) (Click to Select Size) Orings - 3" to 3.875" (76.2 to 98.4mm) OD (Sold Individually) (Click to Select Size)

Orings sized 3" to 3.875" Outside Dimension (OD). Use to stop First Contact Polymer from flowing on or under optics retaining rings. Measure the Inside Dimension (ID) of your retaining ring to select the correct oring size OD from the drop down menu. Orings 3" to 3 7/8" are sold individually.

Our Price: $3.50
Orings - 4" to 4.875" (101.6 to 123.8mm) OD (Sold Individually) (Click to Select Size) Orings - 4" to 4.875" (101.6 to 123.8mm) OD (Sold Individually) (Click to Select Size)

Orings sized 4" to 4.875" Outside Dimension (OD).  Use to stop First Contact Polymer from flowing on or under optics retaining rings.  Measure the Inside Dimension (ID) of your retaining ring to select the correct oring size OD from the drop down menu.  Orings from 4" to 4 7/8" are sold individually.

Our Price: $3.75
Orings - 1" to 1.875" (25.4 to 47.6mm) OD (Bag of 5) (Click to Select Size) Orings - 1" to 1.875" (25.4 to 47.6mm) OD (Bag of 5) (Click to Select Size)

Orings sized 1" to 1.875" Outside Dimension (OD). Use to stop First Contact Polymer from flowing on or under optics retaining rings. Measure the Inside Dimension (ID) of your retaining ring to select the correct oring size OD from the drop down menu. Orings 1" to 1 7/8" are sold in bags of 5.

Our Price: $4.75
Orings - 3/8" to 7/8" (9,5 - 22.2mm) OD (Bag of 5) (Click to Select Size) Orings - 3/8" to 7/8" (9,5 - 22.2mm) OD (Bag of 5) (Click to Select Size)

Orings sized 3/8" to 7/8" (.325" to .875") Outside Dimension (OD). Use to stop First Contact Polymer from flowing on or under optics retaining rings. Measure the Inside Dimension (ID) of your retaining ring to select the correct oring size OD from the drop down menu. Orings 3/8" to 7/8" are sold in bags of 5.

Our Price: $4.75
Orings - 2" to 2.875" (50.8 to 73.0mm) OD (Bag of 5) (Click to Select Size) Orings - 2" to 2.875" (50.8 to 73.0mm) OD (Bag of 5) (Click to Select Size)

Orings sized 2" to 2.875" Outside Dimension (OD). Use to stop First Contact Polymer from flowing on or under optics retaining rings. Measure the Inside Dimension (ID) of your retaining ring to select the correct oring size OD from the drop down menu. Orings 2" to 2 7/8" are sold in bags of 5.

Our Price: $5.25
Orings - Custom Size 5 To 10 Inch (127.0 to 254.0mm) OD (Sold Individually) Orings - Custom Size 5 To 10 Inch (127.0 to 254.0mm) OD (Sold Individually)

Orings are used to stop First Contact Polymer flow on or under optic retaining rings (or retaining flanges if retained from backside). We will manufacture a custom sized oring to fit your optic.

Measure the Inside Dimension (ID) of your retaining ring, mirror cell, etc. to select the correct oring size OD and enter the size in the space provided. Custom size orings are sold individually.

Our Price: $8.25
Orings - Custom Size 10 to 20 Inch (254.0 to 508.0mm) OD (Sold Individually) Orings - Custom Size 10 to 20 Inch (254.0 to 508.0mm) OD (Sold Individually)

Orings are used to stop First Contact Polymer flow on or under optic retaining rings (or retaining flanges if retained from backside). We will manufacture a custom sized oring to fit your optic.

Measure the Inside Dimension (ID) of your retaining ring, mirror cell, etc. to select the correct oring size OD and enter the size in the space provided. Custom orings are sold individually.

Our Price: $9.95
Oring Kit - 1" to 4.75" Oring Kit - 1" to 4.75"

An oring kit for someone with a wide variety of optics!  Contains a full range of orings from 1 inch to 4.75 inches, in 1/4 (one fourth) inch increments, and also a single edge razor and super glue to custom fit the orings if desired.

Our Price: $23.50
   
 

Shipping Restrictions
We cannot ship to P.O. boxes. We must have a physical address in order to ship First Contact Polymers.