the tolerance ring 1 a extends entirely around the circumference of the shaft 3 in contrast to the tolerance ring 1 shown in fig1 the tolerance ring 1 a in fig2 has a strip of projections 14 a extending radially inwards towards the centre of the ring 1 a and thus towards the shaft 3 each projection 14 a has a peak 17 a and each of the peaks 17 a are in contact with the outer surface 31 of the shaft 3 as the apparatus in fig2 is fully assembled each of the projections 14 a is compressed by the shaft 3 annular regions of the ring 1 a that have no formations are indicated by reference numerals 15 a and 16 a the radially outer surface of the tolerance ring 1 a is located at a point along the surface 21 in the bore 22 of the housing 2 the ring 1 a has a u201c peak radius u201d which is the distance between the longitudinal axis of the bore 22 through the housing 2 and the peak 17 a of a projection of the series of projections 14 a when the projections 14 a are not compressed in this embodiment each of the peaks 17 a is the same distance from the longitudinal axis and so the peak radius may be measured from.