ACOG TA31 RMR 4x32 Red Fibre Optic Sight Scope with RMR. X4 Acog Scope with red chevron reticle that is illuminated by the fiber optic. Aslo has a piggyback mount and a RMR red dot which it attaches too. Scope works perfectly and is brand new and not been used. As can be seen from photos, this scope has been filled with nitrogen and sealed to prevent internal fogging.