The Fulham FreeLite line of photoluminescent exit signs requires no batteries or electrical power. During the day, FreeLite technology absorbs light into the company’s proprietary photoluminescence materials, which later shine when ambient lights are turned off. The signs don’t need testing or maintenance (other than occasional dusting) and won’t fail during power loss. FreeLite technology is fully recyclable. Unlike Tritium exit signs, FreeLite doesn’t use radioactive gas.