Abstract: A mouth-blown sports' whistle with a resiliently compliant ring of material surrounding the end of the whistle for engagement with the operator's mouth to prevent injury to the whistle user's teeth and having a whistle body with a C-shaped member forming a finger-gripping arrangement therewith and depending therefrom, the C-shaped members being bridged by a length of tubing formed of an elastomeric substance having a memory slipped over the ends of the C-shaped member, the tubing forming a substantially improved finger gripping and cushioning arrangement with the C-shaped member.

Abstract: Security apparatus which is operable to protect valuables by triggering an alarm and/or by defacing or rendering the valuables unusable on a change of pressure in a pressure sealable chamber. In a first embodiment suitable for use as a cash box (10), the valuables are received in a hollow receptacle (21) surrounded by a vacuum chamber (22) and a dye bomb (39) within the receptacle (21) is exploded on loss of vacuum within the vacuum chamber (22). In a second embodiment suitable for protecting the contents of mail bags, a hollow plug structure (63) is fitted to the nekc of a mail bag. The plug structure (63) has an opening (65) communicating with the interior of the mail bag so that the interior of the plug structure (63) and the interior of the mail bag can be evacuated to form a vacuum chamber. The plug structure (63) carries a dye container (69) from which dye is sprayed into the mail bag on loss of vacuum within the chamber.