This is a unique float for several reasons:

1)  The WP #166 mark 'Sun' is usually found on 3", 5", and 8" floats

2)  This is a smaller version of the WP #166 maker's mark than I've seen before on 2 inch floats; it's only 1/4' wide and 1/2" tall

3)  The Lime or Mint Green color is distinctly unusual

4)  It's a crudely constructed float.  It's out-of-round, the top half of the float is very thick & heavy, and there are bits of grit caught in the glass

This float has excellent provenance having come from the ex-Col. Rich Richardson collection.