9" Harris Types of Tactical Bipods, with 20mm picatinny mounting adaptor:

Harris types of Tactical bipods are quality manufactured with heat treated steel and hard alloys.    They are quick-detachable and clamp to the Q.D. stud of bolt action rifles with conventional stock design. Hinged bases have tension adjustment to eliminate tremor or looseness in the crotch area of the bipods. And they're all-weather black anodized finish. Pivot head can not rotate, one direction aiming only.

They come in 3 different sizes of heights: AS-ZJ01-6", AS-ZJ01-9", and AS-ZJ01-13".