Momentary Action 2-3/8"" Red Button. Single Gang Mounting. Large Button Caps: Supplied with a large 2-3/8 diameter cap to meet code requirements for some localities. The caps can be supplied in colors other than red as may be needed for electrically locked exit doors. Safe Redundant Contacts: Dual contact blocks, one normally open and one normally closed set are furnished standard. Allows the magnetic lock power to be cut by the normally closed contacts upon switch activation while simultaneously signalling an access control panel with the normally open contact block. Since both sets of contacts are electrically isolated from each other, there are no problems with voltage compatibility. Plate Engraved "EMERGENCY RELEASE" Stainless steel switch plate.