This oring kit is an excellent choice for someone with a wide variety of optics. The kit 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. An oring can be cut and glued together to form fit to any size mounted optic if one of the orings in the kit does not fit to the user's requirements.
These are chemical resistant orings that do not swell when in contact with the polymer. Do not use cheap Butyl or Buna orings, they will absorb solvents, swell and can break down leaving residue.
NOTES: 1. If the orings are not flat when received and do not lay flat on your optic you can lay on a flat surface and apply mild heat with a heat gun and the orings will flatten. Allow to cool then apply to your optic! 2. The oring may trap a very thin layer of polymer underneath and leave polymer residue when peeled. This possible situation can be avoided by coating one side of the oring with polymer (or dipping), and once dry you can set in place and use per directions.