- 2 Yo-yo halves with a response system consisting of pads, flowable silicone, o-rings, or starburst
- Threaded axle
- Shims (Optional addition on some yo-yos)
- Response system
- A looped string
This is the basic anatomy of a modern player's yo-yo. Although there are variants of these parts, such as larger bearings, different-shaped yo-yo halves, and different response systems, the basic concept is the same.
The guys at One Drop have put together a cutaway diagram of a yo-yo with the names they have given to the body areas: