TechSIL EMI/RFI Shielding Conductive Elastomer “D” Profile Molded O-Rings come in nine different sizes. They come with foot prints ranging from .078” to .240” and have Inside Diameters ranging from .410” to 3.910”. TechSIL molded parts can be molded out of all sixteen standard compounds. The O-Rings can be used with or without a groove. Additional sizes and compounds are available upon request.