PURPLE - Lets Go Pet Walker Bicycle Dog Leash for Medium/ Large Dog Light weight - Only 600g* (FULL SET, Seat post clamp + Leash). All aluminum made. Aluminum 6061, various color: Blue, Red, Purple and Gold. Fits all kind of bike - Fits all size seat post 25.4-31.8mm Easy install and quick release, no tool needed Safety- spring provide elasticity and avoid an unexpected pulling force while your dog meets your neighbor's cat. A biker will not be controlled by the dog. And Unhindered - Will not interrupt a biker's thigh Fits for medium / Large size dog