A drug delivery device having a collar and a linkage component. The drug delivery device includes a variable dose setting mechanism, a fixed dose setting mechanism, a single dose setter, a collar, and a linkage component. The variable dose setting mechanism is operably coupled to a primary reservoir holding a first medicament and/or fluid. The fixed dose setting mechanism comprises a fixed dose piston rod that is operably coupled to a secondary reservoir holding a second medicament and/or fluid. Further, the single dose setter is operably coupled to the variable dose setting mechanism, and the collar is disposed on the variable dose setting mechanism. Still further, the linkage component may be disposed on the fixed dose setting mechanism, wherein the linkage component is capable of engagement with the collar. The delivery device is capable of delivering the second medicament and/or fluid by way of at least one discrete pulse of the second medicament and/or fluid.