Herm Sprenger 3.0mm Chrome Narrow Round Links 70cmHerm Sprenger Chrome Narrow 3mm 51012 Dog Check Chains Round Narrow Links Additionally the Herm Sprenger Chrome Narrow 3mm Check Chains dog collars are the most popular type of link style used, especially used by not only trainers and professional dog handles but by the everyday dog owner. Suitable for small to medium dog breeds these chains are often used for dog obedience training and by the everyday dog owner. The 3. 0mm gauge, Sprenger Check