This is a fishing tool called "Sao Yasume Fune II" by YAMASHITA. It is used by inserting it into the rod holder hole on the side of the boat. It's a convenient item for temporarily resting your rod while fishing, or for taking your hands off the rod when attaching bait or handling fish. It has a function to prevent the rod from sliding sideways or falling due to the boat's movement or wind. The bright color makes it easy to find even if it's accidentally dropped. Thank you for viewing.