spring contact guards against slipping for optimal contact
suitable for any type or breed of dog
no more side deviations
NOTE from Martin Systems:
Feathers break due to screws that are not screwed in equally (there is more tension on one side and it turns and breaks), due to leash pressures, collar pressures ( like pinch collars), dogs that flip around in the kennel, dogs that scratch. All of these are physical pressures not covered under warranty.