Fuente: WIPO "rice" A self-gripping resilient split-ring collar having a circular hole with a diameter which is normally smaller than the diameter of the shaft over which it is intended to circumferentially extend. The collar includes double camming action structure which coacts with the ends of the collar adjacent the split therein to yieldably urge the ends away from one another to increase the diameter of the circular hole, thus permitting the collar to freely circumferentially engage the shaft whereby it may be moved to and fro along the length of the shaft to the desired location thereon. One embodiment of the camming structure is fixed to the collar and is adapted to receive a hand tool, e.g., a screwdriver or the like, for manipulation thereof. Another embodiment of the camming structure is removable from the collar as a peculiar tool, the tool also being disclosed herein.