Файл:MI6 concealment device - Signet rings.png

Some of the many ingenious types of concealing devices prepared for the use of SIS and its agents. Signet rings are of varying shapes and mechanisms. They are primarily intended for the carrying of suicide tablets, but can also be used for small jewels, micro-photographs or messages written on very small pieces of fine paper. [From Left to Right, Type 1:] This type has a screw-on top which must be unscrewed by a turn to the right to reveal the concealed cavity. [Type 2:] The top of this ring is pivoted in one corner, allowing it to be opened by a sliding movement. The concealed cavity is below this sliding lid. [Type 3:] The top of this ring has a single pivot in one corner allowing it to be opened by a sliding movement. A miniature compass is concealed in the cavity thus revealed. [Type 4:] The top of this ring has an inlaid stone or jewel. This has to be prised out to reveal the concealed cavity beneath.