extends well beyond the body 26 in a downhole direction as illustrated herein a tapered portion 42 of the mandrel 30 connects a first dimensioned portion 46 to a second dimensioned portion 48 of the mandrel 30 the first dimensioned portion 46 is radially smaller than the second dimensioned portion 48 movement therefore of the mandrel 30 in an uphole direction relative to the dog s 34 and body 26 causes the dog s 34 to move radially outwardly as the dog s 34 ramps along the increasing radial dimension of the tapered portion 42 referring to fig2 and 3 a decelerator assembly 22 falls in a downhole direction within the tubular 14 until the distal end 38 of the mandrel 30 contacts the downhole structure 18 at which point the mandrel 30 ceases motion in relation to the tubular 14 continued downward movement of the rest of the decelerator assembly 22 causes relative longitudinal motion between the body 26 and the mandrel 30 this relative motion causes the dog s 34 to ride along the tapered portion 42 of the mandrel 30 from the first dimensioned portion 46 toward the second dimensioned portion 48 in so doing the dog s 34 moves radially outwardly through windows 54 in the body 26 as the dog s 34 ramps along the tapered portion 42 as best seen in fig3 as the dog s 34 travels radially outwardly it enters a recess 56 in.