Atlas Bipods Sig Sauer Cross Buttstock Rail Kit Black. 05in 1913 Picatinny Rail that installs directly onto the folding buttstock of the SIG SAUER CROSS rifle to allow for mounting of any of our PRM style of Accu-Shot Monopods. Specifications for Atlas Bipods BT78 Sig Sauer Cross Buttstock Rail Kit: Manufacturer: Atlas Bipods Color: Black Length: 2.05 in Weight: 0.59 oz Finish: Mil-Spec Type III Class 2 Fabric/Material: 6061-T6 Aluminum Country of Origin: USA Features of Atlas Bipods Bipods BT78 Sig Sauer Cross Buttstock Rail Kit Installation requires two factory 10-24 threaded holes spaced approximately 1.57in apart as found on our sample SIG SAUER CROSS. No modification is required. Use of a thread locker upon installation is suggested. Package Contents: Atlas Bipods Bipods BT78 Sig Sauer Cross Buttstock Rail Kit Two 10-24 x 3/4in Flat Socket Cap Screws Atlas Bipods BT78: Bipods BT78 Sig Sauer Cross Buttstock Rail Kit Black