This float has 4 symbols on it's seal; one symbol in each of the four quadrants. The four symbols are: A ア - Sa サ - Ha ハ - Ra ラ.
This is an undocumented maker's mark.
It also has a nice light green colored seal button.
The float is 2 1/2 inches wide.
This float has excellent provenance having come from the ex-Deborah Hillman collection.