Updated: These friction inserts only fit the old style Shinwoo products and we no longer have these in stock. Shinwoo has since upgraded their friction materials making these obsolete. Make sure you have an old style Shinwoo product before purchasing this. Three different rubber replacement inserts for Phantoms and ZanNavi's. The Green ones are stock, just like you got with your phantom. The Blue ones are lower response for a higher level of play. The Black is near Zero response. Tune your yo-yo with manufacturers upgrades and replacement parts.