SureFil SDR Flow + Bulk Fill Flowable, Universal Shade, 0.25 Gm Compula Tips Refill, 15/Pk. Composite Base used for posterior restorations, that allows for bulk placements up to 4 mm with a short 20-second cure time. SDR (Stress Decreasing Resin) Technology optimizes the way that the polymer network is formed while curing, reducing the polymerization stress caused by polymers that become too taut. Contains fluoride, radiopaque.