The Green Seal button really sets this float apart and I think makes this a great display float.
It has a nice example of WP #7-A Maru Se ㋝ stamp, that's commonly referred to as Otaru T.
Green seals that are marked are pretty rare; way more rare than marked blue seals or cranberry seals.
This float measures 3 1/2 inches in diameter.
Found on Hokkaido Island, Japan.