The Ninth Edition of the Standard for Connectors and Switches for Use with Burglar-Alarm Systems, UL 634, is being issued as an American National Standard. The following revisions have been made to the standard: (a) requirements in Sections 49 - 57 were revised to apply to both High Security Switches (Level 1) and High Security Balanced Magnetic Switches, BMS (Level 2), (b) Sections 58 - 65 were added for High Security Balanced Magnetic Switches, BMS (Level 2), (c) standard references were updated, (d) the scope paragraph addressing investigation of new and different features of products was deleted, and (e) editorial corrections were made.