illustrated in fig1 shifting tool 10 may include top sub 12 shifting tool key 14 reciprocating assembly 16 and bottom sub 18 top sub 12 and bottom sub 18 are positioned in spaced apart relation and interconnected by reciprocating assembly 16 shifting tool key 14 is positioned on the outer surface of top sub 12 between upper key retainer 24 and lower key retainer 26 upper and lower key retainers 24 26 maintain shifting key 14 in position relative to top sub 12 upper and lower key retainers 24 26 are preferably slidably positioned on top sub 12 and held in place by mandrel 32 shifting tool key 14 may include recess 20 that accommodates biasing means 22 biasing means 22 are capable of causing the radial outward expansion of shifting key 14 biasing means 22 may be a spring such as a grasshopper spring or butterfly spring shifting tool key 14 may include an outer profile containing engagement shoulder 28 and releasing shoulder 30 when radially expanded the outer profile of shifting tool key 14 cooperates with a mating profile on the inner surface of internal sliding sleeve 44 of mechanical sliding sleeve valve 42 for example engagement shoulder 28 may cooperate with mating shoulder 52 of internal sliding sleeve 44 as shown in fig2 again with reference to fig1 reciprocating assembly 16 includes mandrel 32 and outer housing 34 the upper.