An antifriction mounting includes a bearing having an inner and an outer ring and rolling bodies between them. A seal closes the lateral side of the bearing between the rings. A pulse generator is rotatable with a rotatable one of the rings, which is either the inner or the outer ring. A non-ferromagnetic cover is outside the pulse generator and also seals the opening into the space between the rings. A rotational speed sensor on or outside the cover scans the pulse generator magnetically without hindrance from the non-ferromagnetic cover. Radio signals may transmit other information besides rotation speed. Appropriate transmitters and receivers for those signals can be placed at the pulse generator and/or the sensor.