The GP2000 is a permutation of the AP2000 where frequency, amplitude, centrifugal force and mass are adjusted to provide optimal productivity in the compaction of sands and gravel. The GP2000 is capable of achieving excellent densities on lifts of granular soils up to 12" (31 cm)*.The GP2000 is a permutation of the AP2000 where frequency, amplitude, centrifugal force and mass are adjusted to provide optimal productivity in the compaction of sands and gravel. The GP2000 is capable of achieving excellent densities on lifts of granular soils up to 12" (31 cm)*.