In addition to all the above, as far as I am led to believe, the Green Box, once activated, (in the event of a fire or other emergency), will allow employees to safely egress from a final exit (secured from unauthorised outside access), should the normal electronic access/egress switch or device become disabled. More importantly, this will also permit external access for fire service personnel without the use of a key or any other similar security device; and as such, (as with the Red MCP counterpart), should be taken into account by the building manager, (or other responsible person), post-fire incident with regards to electronic re-set, replacing the "break-seal" and thus re-establishing security to the premises. Sorry but I feel this is a point worth making for those responsible for building security.