Manufactured in mirror polished Die Cast Metal the M-KE is a part of the Key Exchange system. It can be provided as a 1 key trapped and up to 9 keys released system. All the keys from the various components of the Trapped Key System that have been mounted on the guards of the application are locked in the Key Exchange block. Only when the first key of the system is released from the isolation switch (or control switch), and power has been removed from the hazard, can the keys in the Key Exchange block be released. And likewise, until all the keys from the guards have been returned and re-inserted into the Key Exchange block, can the first key (isolation switch or control switch) be released - allowing it to be replaced in the isolation switch (control switch) to enable power to be re-applied to the machinery or hazard.