These are the requirements:
- Hands-free, attached at the waist (of the human)
- Non-static, to prevent jolts
- With handle near the dog, for extra control
- Brightly colored
- With replaceable parts (clips and elastic)
This is NOT a leash that works well on a collar - it's meant to be used attached to a harness, on the back of the dog, but it could be modified by moving the elastic towards the human.