Abstract: A stop member for a device such as a syringe is inaccessibly disposed in a sleeve member. The ring member is also disposed about a portion of the stop member and in the sleeve member. The ring member is connected to the inside of the sleeve member by means of a frangible connection. When the sleeve member is twisted. the sleeve member and its connected ring member freely rotate about a portion of the stop member at the end of the syringe. When the sleeve member is axially pulled off the end of the syringe, the frangible connection breaks, and the sleeve member is removed, leaving the ring member and stop member disposed on the end of the syringe thereby indicating that the prefilled syringe has been tampered with.