Offered by Forrest Mountaineering in 1974, this single cable plastic Foxhead chock only available in the #3 size. The photos show that the casting for the plastic version was unique and not a direct copy of the aluminum version.
When I climbed with Harvey T. Carter in the mid-1990s he had one of these on his rack. It was a favorite of his and he loved to set it into placements with a few whacks of his hammer. The damn thing was almost impossible to clean sometimes! I would laugh every time I saw it used because it became more and more beat up, more rounded and scared, each time. The last time I saw it at his memorial service in Garden of the Gods, Colorado it was just a blue blob and whittled down to about a #2 size.