I found this doing a google search, b/c I was curious.
Snap-On NS-4C 1/2-Drive "Nut Spinner" Flex-Head Speeder
Fig. 124. Snap-On NS-4C 1/2-Drive Flex-Head Speeder, with Insets for Construction and Marking Detail, 1947. Fig. 124 shows a 1/2-drive Snap-On NS-4C flex-head speeder, marked "Made in...