Roo-Yo is a yo-yo manufacturer based in Italy, prudcing high-end aluminium yo-yos. Their first products, the Roo-Yo and Roo-Yo SV (Small Version) appeared in 2005, featuring innovative golfball-like dimples, meant to lessen friction when doing grind tricks. Coincidentally, the dimpled design did the opposite, and the yo-yos were 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 seat where a friction sticker or normal o-ring would normally go. It is very versatile, as the player can control response by pulling the o-rings further outward of the grooves 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 misinterpreted the explanation, and made the grooves perpendicular to the yo-yo instead.