Harris 6-9 or 9-13swivel notch. My bud has an atlas, it's nice, but i prefer to lock the swivel and the Harris notch leg adjustment is easier and quicker. Where my range is we can shoot to 1340 yds, only negative is that the shooting position is running downhill slightly. Bipods always need to be out extended longer then when on flat ground, his atlas, when extended, seem to have sloppy legs. Not my cup of tea for a 250.00 bipod.