This Training Collar is designed to have a higher number of links at the same length, providing a more targeted impact on the dog. It also has a high stability due to the 3 mm wire thickness. Recommended as an alternative to the 2.25 mm training collar for larger dogs. Features: * pull limitation on the length of the assembly chain * smaller links with larger wire thickness for even more precise impact Length: 20" (50cm) Wire gauge: 3.00 mm Two versions of the collar to choose from: * with 2 rings * with 1 ring and 1 swivel