A heavy cat rig (Omoneko) that spreads due to its greater flight distance, sensitivity, and ease of handling in the so-called “cat rig” that uses a nail sinker.However, the problem of “the sinker comes off” that worries anglers as the weight increases.In order to thoroughly solve this problem, we adopted a screw-type keeper and created a special sinker that is easy to handle and allows you to cast with confidence.The weight shape adopts a cylindrical shape that is stable at the bottom and makes it easy for the worm to stand while being familiar with the straight worm.Its shape can be attached not only to cat rigs, but also to swim baits and offset hook rigs, making it a convenient sinker that enables weight reinforcement for various rigs.