3/9/20 - The E-500 provides dampness protection that is ideal for small spaces such as your gun safe. It prevents rust to guns and expensive ammunition and other damage caused by excess moisture. This eco-friendly dehumidifier silently and reliably protects against mold, mildew and moisture in areas larger than the Eva-Dry E-333, units and lasts 30-60 days before renewing. Once the indicator beads have gone from orange to green, simply plug the unit into a wall socket to recharge! Special features of the E-500 includes: the unit works in areas up to 500 cubic feet, requires no batteries or cords for use, is 100% renewable, works up to ten years, is compact/silent, always spill and mess free and is non-toxic, child and pet safe! The unit measures 8″ L , 2 ½” W, 5 ½” H.