3.0 SHORT VERSION – Black Stainless SteelThis 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: 24" (60cm) Wire gauge: 3. 00 mm