HES 9400 605 Fail Safe/Fail Secure, Complete 12/24VDC Electric Strike, Surface Mounted, 1/2" Thickness, Bright Brass The 9400 series is a slim-line, surface mounted electric strike designed to accommodate rim exit devices with a 1/2" Pullman latch. All components are completely encased within its 1/2" thick stainless steel housing, so no cutting on the frame is required for installation. Simply place the electric strike on the surface of the frame, align it with the exit latchbolt, and install.