After removing all ballasts, rewiring per diagram (no errors in wiring diagram), installing 84 bulbs (4 per fixture), and applying included LED conversion warning label, I had absolutely no concerns. Every light worked right out of the box. Lights are used minimum 5 hours a day in a commercial setting, and after 2 months still not a single problem.We replaced because old ballasts were becoming non-functional, and this option was actually cheaper than replacing both ballasts and flourescent bulbsSee full review