Round Spinning Objects (RSO) is a premium yo-yo brand created by Elvin Lim, a radiologist and avid yo-yo collector from Singapore. Specializing in titanium and stainless steel designs, each RSO yo-yo tells a story through its theme and packaging, with an average of two prototypes per model before release. Their collector-focused designs like the Spaceship, Bowl, and Burger have earned a cult following among enthusiasts worldwide.