Rubber O-ring with square cross section profile. Sold individually.
If the male SCT thread on your telescope is shorter than the female SCT threads on an SCT diagonal, then the diagonal will not lock and will continue to rotate freely. Inserting this rubber O ring into the SCT adapter on the diagonal and then screwing it on to the telescope will overcome this issue. Depending on the difference in lengths of the SCT threads on either side (the telescope and the diagonal), you may need to stack more than one O-ring.
- Nominal Inside Diameter: 1-11/16 in (1.68 in, 42.86 mm)
- Nominal Outside Diameter: 1-7/8 in (1.88 in, 47.62 mm)
- Nominal Width: 3/32 in (0.09 in, 2.38 mm)
- Cross Section Shape: Square
- Material: Buna-N (Nitrile Rubber)
- Temperature Range: -30 to 250° F
- Hardness: 70A Shore Durometer
- Color: Black