Herm Sprenger Chrome 3mm | Heavy Round Links Check Chain Dog Collar Herm Sprenger Chrome 3mm – Heavy Round Links Check Chain Dog Collar – The Heavy Round Links are the most popular type of link style used, often used by not only trainers and professional dog handles but by the everyday dog owner. Each mm link thickness is suitable for different uses. The 3mm check chains are the one of our medium, slightly heavier sizes available. Suitable for medium to large dog breeds these chains are often used for dog training and by the everyday dog owner. About each finish: Black Coated Stainless Steel check chains, are more expensive than Chrome plated, but the stainless steel chains are also more suited to dogs that live in coastal areas or spend time in water. Normal steel will become dull, and, especially with time spent in saltwater, will roughen the plating and become rusty. Stainless Steel has a higher breaking load producing greater security and longer life. Link Thickness 3mm, Chain Length 40cm, 45cm, 50cm, 55cm, 60cm, 65cm, 70cm,