My favorite ones are OP's (other peoples)
Those are the "free" ones I find hanging in trees, washed up on the bank, or hung on underwater wood.

Who makes them ?? Most I find are the Comal pear shaped & cigar shaped styrofoam, or Thill styrofoam pear/oval shaped ones. I don't much care for the spring end style floats, so I leave them for someone else.

... cp