Setback switch for safe and arm

A switch mechanism is provided that has a tubular enclosure; a contact pin electrically insulated from the tubular enclosure; a g-weight positioned inside the tubular enclosure and movable from an open position to a closed position; and a transparent closure that encloses one end of the tubular enclosure. The g-weight is in electrical contact with the contact pin and the tubular enclosure when the g-weight is in the closed position, such that a continuous electrical path exists from the contact pin to the tubular enclosure. The g-weight is for moving from the open position to the closed position when the switch mechanism is subjected to an acceleration greater than a threshold acceleration. The g-weight is visible through the transparent closure such that the position of the g-weight can be determined without removing the transparent closure from the tubular enclosure.