Prong collars should be put on and taken off before and after daily training sessions. This collar is made of interlocking links, each with two blunt prongs that meet the dog's skin when the collar tightens.
This collar is to be used when training with a lead. It is NOT recommended that you leave it on unattended dogs.Small collar is 2.3mm x 14" lightweight. Medium collar is 3.0 mm x 18" medium weight.