A fastening unit for fastening an object to a profile element includes a first layer of vibration isolating material arranged on an underside of a washer element and a second layer of vibration isolating material arranged on an upper side of an oblong anchoring element. The oblong anchoring element and the second layer of vibration isolating material each have a width that allows them, preferably in unity, to be aligned with a longitudinal slot of the profiled element inserted therein, and then turned to receive flanges of the profile element between the first layer of vibration isolating material and the second layer of vibration isolating material, so as to provide, at least in a fastened state of the fastening unit, a barrier for vibrations between the washer element and the flanges and between the oblong anchoring element and the flanges.