This is a tool used to sink bait underwater when fishing. Since fishing sinkers are mostly made of lead, their weight can be easily adjusted by carving off excess lead with a knife or small scissors. Based on the shape of sinkers, they are categorized into a lead sheet (generally used for fishing with a roll and paper thin compared to other sinkers), a weight sinker (made of lead to act as both weight and sinker), a triangular sinker, a wheel sinker, a clam sinker, a mung bean sinker, etc.