Fixed PointRSFP1 with cross and 5/8? thread with protection capRSFP1-A protection cap in aluminumAluminum plate with engraved cross as fixed pointThe measuring point has a 5/8��� thread for screwing on a prism or measuring instrument.When used as a fixed point on the floor, this point should be surveyed with a prism so that if necessary, e.g. suspected moving of the fixed point due to foul play, it can be checked quickly and easily.RSFP1 is supplied with a plastic or aluminum (RSFP1-A) protection cap for the 5/8��