RooYo
From YoYo Wiki
RooYo is a manufacturer based out of Italy, making high-end aluminium yo-yos. Their first products, the RooYo and RooYo SV (Small Version) appeared in 2005, featuring an innovative golfball-like dimple finish, meant to lessen friction when doing grind tricks. Coincidentally, the dimpled design did the opposite, and the yo-yo is not very well suited to grinds.
Roo-Yo is also credited for the S.I.D.R.O.M.S. (Sistema Innovativo Di Ritorno Oring Micro Siliconici) response system, consisting or four small o-rings, placed in grooves around the bearing where a friction sticker of normal o-ring would normally go. It is very versatile, as the player can control response by pulling the o-rings further out of the groove for more response, or pushing them in futher for less response. Originally, the idea was to have four o-rings placed flush on the surface, parallel to the bearing, but apparently the Roo-Yo machinist misheard the explanation, and made the grooves perpendicular to the yo-yo instead.
