Electric Light Unit Power Functions with Black PF Connector Lead, LEGO® Part# 61930c01. Use the power functions electric light unit to light up your creations! Came in sets 41999 (4x4 Crawler Exclusive Edition), 8297 (Off Roader), 8870 (Power Functions Light), 8293 (Power Functions Motor Set), 9688 (Renewable Energy Add-on Set), 10268 (Vestas Wind Turbine), and 4999 (Wind Turbine - Vestas Promotional). Tested to ensure it works. 

Power Functions remotes, motors, batteries, lights, sensors and hubs take your builds to the next level.