Herm Sprenger Black Russian Terrier Chrome Plated Steel Fur Saver Collar - 51604 (02) 1/6 inch (4 mm) - Size 21 inch (54 cm) for Dogs with Neck Size of 18-19 inch (45-48 cm) Steel chrome plated Corrosion resistant Fits Black Russian Terrier well 2 O-rings for leash attachment 4 mm link size