Atlas Bipods 2.05in 1913 Rail Radius Back with slotted hole spacings 1.2-1.6in Black. 05" 1913 Rail has a center to center spacings 1.2 - 1.6". Two Button head machine screws can be used (not included see BT1517) to attach this rail to the forearm of standard rifle stocks. The can also be attached to a horizontal surface on the Butt section to attach our Precision Rail Monopods. Specifications for Atlas Bipods 2.05in 1913 Rail Radius Back with slotted hole spacings 1.2-1.6in: Manufacturer: Atlas Bipods Color: Black Country of Origin: USA Package Contents: Atlas Bipods 2.05in 1913 Rail Radius Back with slotted hole spacings 1.2-1.6in Atlas Bipods BT49 2.05in 1913 Rail Radius Back with slotted hole spacings 1.2-1.6in Black