a transverse slot 32 which opens into the head 20 from one side the same side as the wall 28 and provides a retaining shoulder 34 for a purpose which will appear hereinafter which extends right around the part 24 of the bore each of the walls 28 28 39 of the shank 16 has a rectangular opening 36 in each of which are accommodated two resilient retainers 38 40 integral with the edge of the opening farthest from the head 20 preferably as shown the retainer 38 has one ratchet tooth and the retainer 40 has two they project beyond the outer wall of the shank 16 so that one pair of teeth i e one at each side of the shank can engage the opposite side of the panel m from the head the three pairs of teeth enabling the body to be readily inserted into and retained in panels of different thicknesses alternatively other means for retaining the body in the hole may be provided instead of the particular configuration of retainers shown the locking member 14 of the illustrative bushing has a hollow shank 46 and an hexagonal head 48 the shape of the head is determined by the means it is intended to use to.