Oxballs invented the modern penisheath by morphing our original penisling to a sheath creating the first sheath that really stay on no matter how hard you play. INVADER is that good and more—our first open-ended sheath with wavy ripples on the shaft, and texture inside, So everyone gets max stimulation. Made of PLUS+SILICONE™, our slick soft silicone & stretchy TPR blend..