A fishing sinker, plummet, or knoch is a weight used in conjunction with a fishing lure or hook to increase its rate of sink, anchoring ability, and/or casting distance. Fishing sinkers may be as small as 1 gram (0.035 oz) for applications in shallow water, and even smaller for fly fishing applications, or as large as several pounds (>1 kg) or considerably more for deep sea fishing. They are formed into many different shapes for diverse fishing applications. Environmental concerns surround the usage of lead and other materials in fishing sinkers.[1]