Shapton Rockstar 320 grit now available! The Rockstar line is the newest offering from Shapton. 320 grit is great for quick fixing Dimension 210 x 70 x 10mm Abrasive Type : (WA) White Alumina Splash & Go Grit : 320 Price : Php 2000.00 Note: The RockStar stones are magnesia-based, meaning they require a bit of care. Avoid soaking them, but keep them slightly hydrated — letting them dry out completely may cause cracks, just like parched earth under the sun.