5 holes adjustment Harnesses: Fits Neck Size 17" - 24" (45-60CM) Fits Chest size (behind front legs) Size 26"- 34" (65-85CM) Collars: Small Size Fits Neck 15-18", 2 " Wide, 20 " Length Medium Size Fits Neck 17-20",2 " Wide, 20 " Length Large Size Fits Neck 19-22",2 " Wide, 20 " Length X-Large Size Fits Neck 21-24",2 " Wide, 20 " Length Note: Before you order,Be sure your dog's neck is suitable for this size (That's very important).   Package Included: 1 x  Dog Harness 1 x  Dog Collars