Attached to a firearm by means of a picatinny rail, the Atlas BT53 SILO provides a soft beanbag like grip when utilizing a narrow barricade, such as a window sill to support your firearm. The front side of the device is knurled to provide extra grip when using something like a tree branch or concrete wall as a forward support. The sides of the device have a thin layer of grippy rubber providing support when firing from around vertical cover like a doorway or corner of a building. The device can also incorporate the BT54 Flush Cup Stud giving the device quick detach capabilities.