S-Biner ID Tag Lock, Stay Attached To Your Pet, Constructed Of Stainless Steel With 2 High Quality Stainless Steel Gates, Center Lock Made Of Tough, Durable Plastic, Clip The ID Tags To 1 Gate & The D-Ring Of Your Pet's Collar Or Harness To The Other, Simple Twist Of The Center Lock The Gates Securely Lock & Stay, Water Resistant & Ultra-Secure.