by gianfranco, published
A new optimized version of gyroscopic keyring with 6 rings, rotating freely in any direction and inseparable !!
Gently move the rings if you want to relax !!!
The external diameter is 4,5 cm.
You can scale up by 5 % ( about 4,75 cm ) or 10% ( about 5 cm ).
If you use brim, clean carefully the internal ring.
