Anti-Rotation Design: Prevents the collar prongs from loosening and unthreading, ensuring they stay secure. Easy Prong Switching: Maintain flexibility without the need for permanent adhesives, so you can adjust prong sizes when switching between dogs. Cost-Effective 3-Pack: Get three Prong Savers in each pack for added convenience—perfect for those prone to misplacing them or with multiple collars. Pressure Fit: Nice tight fit to ensure it doesn't slip off during use. Save your Halo collar prongs by keeping them secure and avoid the hassle of lost contact tips with the Prong Fastener. Designed as a cost-effective solution for pet owners, the Prong Fastener prevents the metal prongs on your Halo 3 & 4 collars from unthreading during daily use. Halo collars come with interchangeable metal prongs that can loosen over time, increasing the chance of losing them. Unlike other solutions requiring adhesives like Loctite, the Prong Fastener is easy to install and allows you to remove and swap prong sizes as needed.