Yo-yos parts:
  • 2 Yo-yo halves with a response system consisting of pads, flowable silicone, o-rings, or starburst
  • Threaded axle
  • Bearing
  • 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:

Body names

Yo-Yo Body Names