SureFil SDR Flow+ is the O.G. bulk-fill composite. Never before did we have a resin composite material that would light cure in 4 mm increments. Since this material debuted, the bulk-fill market has blown up. It's off the chain. You can't read a dental publication without seeing bulk-fill composites everywhere. They're all up in that. SureFil SDR Flow+ by Dentsply Sirona (first brought to market by Dentsply Tulsa) started it all and is still a great option today.