Packer setting device, comprising a tubular (10) with a plug housing (14), said plug housing having an internal, through running boring (12) with an internal wall (12a), a breakable plug (16) seated in a load ring (22) axially movable within the boring (12) between a first position in where the plug (16) is with a distance to a breaking pin (18) and a second position in where the plug (16) is forced against the breaking pin (18), said load ring (22) is resting on a shear ring (20) with an annular shear lip (20a) to prevent axial movement in the first position until the shear lip (20a) is subjected to a force higher than a predetermined force, wherein the annular shear lip (20a) of the shear ring (20) extend radially inward in the boring (12), and the breaking pin (18) is resting on the shear ring (20), and said breaking pin (18) is accommodated in a pocket (28) on an outside of the load ring (22).