Folding stack plate for foregrips

A foldable adapter for firearms, comprising:

• a top plate having an upper facing surface and a lower facing surface, the plate having a pair of clamp rails, and a rotatable knob for allowing the clamp rails to move toward or away from each other;
• a bottom plate having an upper facing surface and a lower facing surface, the bottom plate having a pair of picatinny rails;
• and
• a pivot end for pivotally attaching the top plate to the bottom plate, wherein the top plate and the bottom plate are pivotable between a position where the top plate and the bottom plate are sandwiched to one another, and a down position where the bottom plate is perpendicular to the top plate, and wherein the adapter is useful for attaching accessories to the firearm.

A foldable adapter for use with firearms having picatinny rails, comprising:

• a top plate having an upper facing surface and a lower facing surface, the plate having a pair of clamp rails;
• a rotatable knob for allowing the clamp rails to move toward or away from each other;
• a bottom plate having an upper facing surface and a lower facing surface, the bottom plate having a pair of picatinny rails:
• and
• a pivot end for pivotally attaching the top plate to the bottom plate,
• a release for releasing the lower plate member from a sandwiched position to rotate;
• and
• a stop for limiting the bottom plate to pivot to a substantially perpendicular position relative to the top plate, wherein the adapter is useful for attaching accessories to the firearm.