REI is a waterproof long connector with a carabiner + a D ring on its respective ends, and can be used flexibly as: CROSSBODY CONFIGURATION for MELLEM CONNECTOR for another gear such as to a dog walking beltProtip –– connect our KNOX to REI to create a multipurpose short 3.5ft leash!NARROW ¾" or 2cm wide, WIDE 1" or 2.5cm wide Please note that heavy use with a pulling dog or extremely cold weather will wear the hardware a lot more than normal and we suggest you to consider WIDE if you have a pulling dog or live in areas that frequently receive heavy snow. • 100% waterproof and will never retain moisture• approx. 30" or 76cm long when laid flat• easy to clean• suggested for pups up to 30lbs or 18kg• single hand clip with a 360 degrees rotatable swivel at one end• odor proof to prevents bacteria growth• rust resistant hardware• box X stitching for lifetime durability