Dog metal spike training collar w/rubber tip coverThis is Extra Large Size CollarChrome plated steel wire, adjustable length,Heavy duty links for strength and durabilityCollar wire size: 4.00 mmCollar (interior) circumference is approximately 23.5"There are ten links, nine links are removableCould be added or reduced some link to fit your dog"s sizeEach link size: 1.25"W x 1.25"H x 1.75"LMade in ChinaShipping from U.S.A.To determine the proper size, measure the circumference of pet"s neck and add 2"if you need to purchase extra links to extend longer, Please contact us when you order