Final answer:
Retractable lanyards can be extended and retracted, are made of durable materials, and are commonly used for holding ID cards or keys.
Step-by-step explanation:
Retractable lanyards are commonly used for holding ID cards or keys and can be extended and retracted as needed. They are designed with durable materials to ensure longevity and functionality. However, retractable lanyards are not suitable for carrying heavy objects.