PRO-LINE – Nano-Hybrid Composite A3.5 – 4.5gm Refill Syringe Only. Size: 4.5gm Refill Syringe. A new resin composite with unique nanofiller technology. The filler loading is 71% by weight. This reportedly provides increased filler loading, better physical properties and improved polish retention when compared to composites containing only nanoclusters.