Dunlop RWS13 Billy Gibbons Mojo Guitar Slide, Porcelain, Extra Large The Reverend Willy's Mo-Jo Porcelain Guitar Slide is crafted of high-fired porcelain and coated in a thick glaze, resulting in tone that's articulate but not too bright It's designed with just the right amount of mass for a thick, singing tone that's as big as Texas The guitar slide features a moisture-absorbing interior to prevent slipping