The Double Erect Squeeze helps in improvement of the glans and upper shaft as it enables blood in lower side of an erect penis into the upper side, thus enabling better girth there.

The Double Static Squeeze requires the use of both hands for squeezing penis shaft. This pressure from squeezing allows higher amount of blood inside the corpora cavernosa and glans due to which it expands and stretches better.

source:okaydick.com