According to many professional anglers McCoy Worm Rattles are the loudest in the industry. Made with high quality pyrex glass and stainless steel balls, the McCoy Worm Rattles deliver a boisterous underwater pitch that makes bass go wild. Ideal for insertion into plastic worms, grubs, and other soft plastics, the McCoy Worm Rattles are the perfect way to add another dimension of attraction to your favorite baits.