The most common stopper is RMS-S, which has two smooth and nitrided jaws. It is optimal for the second setup, when OK-VISE clamps are used with full force. Friction level is adequate even for roughing and other types of machining where high forces occur.
The accuracy from every serrration to the jaw surface is ± 0.01 mm.
RMS-S2 is more narrow than RMS-S, about the size of a B-series clamp.
RMS-S3 is higher than RMS-S.