Flat adjustable nylon collar made by Herm. Sprenger in Germany; uses heavy duty nylon webbing along with nickel plated, rust free, very highly polished metal hardware, giving you a tensile strength of 150kg.
To calculate the correct size collar for your dog, please measure your dog's neck (where the collar will sit) using a tape measure, then ensure that you can fit two of your fingers under the tape; choose the collar that will give you the greatest adjustment, or in the case of young dogs, you may be wise to allow for growth.
When fitting the new collar to your dog you will need to allow enough room to fit your two fingers underneath it again, any more than this and your dog will be able to "back out" of the collar when you have a lead attached to it, any less and you may choke your dog.
Sprenger's legendary quality shines through with this product, they've taken an everyday item and turned it into a product that, you can be sure, will outlive your dog (& probably the next one as well).