HES 9700 629 Fail Safe/Fail Secure, Complete 12/24VDC Electric Strike, Surface Mounted, 3/4" Thickness, Fire Rated, Bright Stainless Steel The 9700 Series is a heavy duty, surface mounted electric strike designed to accommodate Corbin Russwin SecureBolt and Yale SquareBolt exit devices. All components are completely encased within its 3/4" thick stainless steel housing, so no cutting on the frame is required for installation. It is field selectable for fail secure and fail safe operation, and for 12 or 24VDC.