Goal Zero Boulder 50/100 Watt Solar PanelGoal Zero's Boulder 50 is a portable Solar Panel that's made to hold it's own outdoors. Composed of extra thick tempered glass, an aluminum body, and padded protective corners, this little boulder can withstand just about anything the weather may throw at it. Use it to charge your Goal Zero portable power packs and power stations like the Sherpas and Yetis. A great solution for extended periods out in the wilderness, camping, RVing, backyard parties,