Image 1 of 1 SM-1 BARREL INSERT KIT SEMI-GLOSS BLACK $65.00 SM-1 barrel insert kit semi-gloss black compatible with SM-1 Tactical and Orbium barrel backs3 inserts .683 .684 .685 Quantity: Add To Cart Added! SM-1 barrel insert kit semi-gloss black compatible with SM-1 Tactical and Orbium barrel backs3 inserts .683 .684 .685