The Accu-shot BT15 is an Atlas bipod picatinny rail mount with an overall length of 3.35” and adjustable attachment spacing of 1.76”-2.78”. The Base has been relieved so it can be used with stocks that have curved surfaces. This model is similar to the 4” Atlas BT17 but slightly shorter to accommodate your rifle’s particular needs. A standard sling stud and sling stud spacer can be used to fasten one side of the picatinny rail down or two button head machine screws may be used. No Hardware (BT1517) is included to attach the rail to a standard rifle stock.