Spiked Training Collar Small 16"Spiked Training Collar Small 16" comfort plus version for more convenient dog training quick release snap hook to quickly put the collar on and off without taking links apart swivel to prevent leash tangling dead ring to back up your prong collar center plate for balanced fit assembly chain for quick action you can customize the size by adding or removing links fastener plates to increase the connection security 16 inches (41 cm) long will do for dogs