The Atlas BT78 Picatinny Buttstock Rail Mount Kit Sig Sauer Cross Black is a 2.05" 1913 Picatinny Rail that installs directly onto the folding buttstock of the SIG SAUER CROSS rifle to allow for mounting of any of Atlas PRM style of Accu-Shot Monopods. Installation requires two factory 10-24 threaded holes spaced approximately 1.57" apart as found on the SIG SAUER CROSS. No modification is required. Comes with two 10-24 x 3/4" flat socket cap screws as seen. Use of a thread locker upon installation is suggested. Machined to Picatinny rail standards from 6061-T6 aluminum with Mil-Spec Type III Class 2 finish. Available in black only. Weight: 0.576 ouncesLength: 2.05"FeaturesAdds a Picatinny Rail to the back of Sig Sauer Cross RifleAllows for mounting of any of Atlas PRM style of Accu-Shot MonopodsMachined to Picatinny rail standards from 6061-T6 aluminum with Mil-Spec Type III Class 2 finishWeight: 0.576 ounces