The Ergal is the version of the Strike One family with a frame in Ergal aluminium alloy, sold by American Precision Firearms and by Arsenal Firearms. Optics ready models take a plate in the slide cut.
Two plates
Type A suits compact dots with an RMSc, DPP or Docter base. Type B suits RMR and RTS based optics.
Fit
Both drop into the factory cut and are also listed for the Pro version.