Double ended Hegar Sound kit with 8 pieces in leather case. Each sound has two sides with a different diameter. The diameter changes in the middle. Made of high polished stainless steel.Diameter of the dilators:Dilator with 3 and 4 mmDilator with 5 and 6 mmDilator with 7 and 8 mmDilator with 9 and 10 mmDilator with 11 and 12 mmDilator with 13 and 14 mmDilator with 15 and 16 mmDilator with 17 and 18 mmThe sizes are stamped in the middle.Total length: approx. 20 cmDiameter: approx. 3-18 mmMaterial: Stainless Steel