Used indoors 3 times and on walks about 2 times. Features: This is a training tool that uses a metallic sound that dogs dislike to instantly teach them that their behavior is incorrect. It is especially effective for correcting excessive barking and pulling during walks. Uses: ・Walking correction for large/giant breed dogs ・Preventing pulling for large/giant breed dogs ・Excessive barking correction When a dog exhibits incorrect behavior (excessive barking or pulling), throw the disc near the dog's feet. The "clanging" metallic sound unique to the disc is very unpleasant for dogs. By repeating this, the "incorrect behavior" becomes associated with the "unpleasant metallic sound," effectively correcting the dog's pulling and excessive barking. It is also a well-regarded tool used by professional trainers. Size/Color ・Disc size: 4.4cm in diameter (palm-sized so it doesn't get in the way during training) ・The disc is shaped to easily produce an unpleasant metallic sound.