Trina Solar's DUOMAX, is a UL/IEC certified frameless module that needs no grounding. DUOMAX comprises two layers of 2.5mm heat-strengthened glass. By replacing the plastic backsheet with heat-strengthened glass, DUOMAX provides UL Fire Class A safety and reduces micro-cracking, PID, module warping, UV aging, and corrosion from sand, acid, alkali, and salt mist.