Hardened Steel Picatinny Rail for Sako 85 M - CONTESSA Rail Length - 160mm Distance Between Bases: 77mm - 100mm Height (BH) - 12.5mm Material - Steel Supplied: 1 Steel Rail, 1 Rear Base, 1 Front Base , 3 wrenches – Mounting screws included Distance between bases: 3 0.000 mm. Rail Base / 77 - 100mm / 31mm (Tail Base)