Titan Vinyl Comfort Tips may be added to your Prong Dog Training Collar to make training more comfortable for your dog, without sacrificing effectiveness. Each tip size should be used with the corresponding Titan Prong Collar size. Vinyl tips for training collar prongs. Adds comfort to training without sacrificing effectiveness. Sized to fit Titan Prong Training Collars (sold separately). Quality guaranteed. Note: Prong and chain training collars are safe, highly effective training tools when used properly and with your dogs safety in mind. Do not use for tie-out. Specifications:. Fine: 2.0 mm. Medium: 3.0 mm. Heavy: 3.3 mm. X-Heavy: 4.0 mm.