These prong collars are designed for the smaller breeds of dogs. The Mini Micro prong collar is designed for dogs weighing less than 5 pounds. The Micro prong collar is designed for dogs weighing over 5 pounds. These collars weigh under 1 1/2 ounces each. They are made in the USA with an imported chain and they are only available in Stainless Steel. Each collar is just less than 1/2 inch wide. The links on these two collars are identical. The differences in the two collars are found in the chain. The Mini Micro prong collar has a lighter chain and a swivel ring. The Micro prong collar has a standard chain and an o-ring instead of a swivel.