size @ 50mm, 70mm, 100mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 210mm, 300mm, 400mm 450mm, 500mm. Price Rs.990/- for 50mm size and it will vary based on the size . Screws are US 1/4-20 inch size and they do not stick out of the rail, which makes this rail a perfect match for Vixen-style and similar mounts. • Material: Black Anodized Aluminum Length: 50mm,70mm,75mm,100mm,120mm,130mm,140mm,150mm,160mm,170mm,210mm,300mm,400,450mm,500mm • Thread: 4 x 1/4-20 inch with 2 connecting screws