Shotgun: Mossberg – Optic: TG / VOR / DOC – Fits TRU TEC Micro (TG8100B TG8100G) EOTECH DOCTER INSIGHT MEOPTA & VORTEX VIPER and other optics with a similar 4-post mount. – Fits Mossberg 500 590 590A1 930 – Mount a dot-optic on drilled and tapped Mossberg receivers – Does not require a Picatinny rail – Mounting hardware and tools included – Allows optic to sit low on the receiver – Lightweight / compact design