Choose a very light leash for your Chihuahua with a small carabiner that is lightweight. Pay attention to robust workmanship, durability, and easy cleaning of the leash. Color or material, on the other hand, is a matter of taste.
A slightly longer leash is often very good for training how to walk on the leash. Short lines, only 1 meter long, on the other hand, are often too tight.
If your Chihuahua is already on a leash, you can give it more freedom with a drag or retractable leash. Such leashes are particularly suitable if the Chihuahua cannot be called absolutely reliably.