Herm Sprenger Prong Collars are the most well known training collars in dog training.  Herm Sprenger products are extremely durable.  Most trainers recommend these for a safer alternative to choke collars.  If placed properly this collar will not apply pressure to the trachea.  Individual links can be added or removed for a better fit.

Made with Chrome-plated steel and has added swivel for ease of use