Abstract: A hand-held device for installing caps on vials having a housing with an outer housing member and an inner housing member. The housing is sized to enable the device to be held in a hand of a user and placed over a vial to be capped. A shuttle member is rotationally disposed within the inner housing for transporting one of a plurality of caps stored in the housing from a cap storage station to a cap installation station within the housing when said device is operated. At approximately the same time, a plunger extending from an inner surface of the outer housing is installs the cap transported to the cap installation station onto a vial. Also described is a cap to be used in the hand-held device. The cap has a substantially flat endwall defining a peripheral edge surface and a sidewall extending therefrom. The peripheral edge surface defines a radius which is substantially less than 0.040 inches.