The glass surface is impact resistant and allows maximum light transmission. Polycrystalline solar cells are encapsulated and bonded to the glass in multiple layers of ethylene vinyl acetate (EVA)and laminated with a white Tedlar? backing insuring long life in severe environmental conditions. A weather resistant junction box accommodates all wiring methods including moisture-tight strain relief connectors and electrical conduit. Bypass diodes insure reliable operation. Anodized aluminum tubular frames add strength and durability to the modules. Pre-drilled mounting holes. UL listed. All SunWize modules carry a limited 25-year, 80% power output warranty.