High-Quality Material:Made of 304 stainless steel collar, Hand Polished,18K Gold Plated.Durable, No Rust, No Tarnished for years of use! It is very strong that cant be pull it apart even with 650lbs of force!How to Choose Collar Size: Wide10MM (0.39"),Length10"-24".Because this dog collar is P-chain design,The size the dog wears can be adjusted to a certain size according to the dog's neck.How to choose the right size-Please measure the length of your dog's neck before ordering.Measure the widest point around your dogs head,and add 2-4 inches for initial collar length for Adjustment.You can refer to the product picture introduction, there are detailed instructions aboveCollar: your dog is easy with our collarSlip Collar:NO tarnish, rust, or break,dog collar is excellentGUARANTEE:If you have any quality problems within 90 Days,you can contact us at any time for after-sales service. For whatever reason, if you don't absolutely love our gold dog collar, just return it, we'll refund .(Or replace it, if there is a problem).