The X-Brain combined the Brain’s centrifugal clutch auto-return mechanism with a butterfly (wing) profile, making it accessible for both beginner looping and introductory string tricks. The wider gap accommodated the string during tricks while still snapping back when spin slowed. The X-Brain was featured in the McDonald’s Happy Meal yo-yo promotion in 1999–2000 and introduced millions of children to butterfly-style yo-yos.
X-Brain
Folio 1152
