The M-Series is the first calibrated plugger and spreader system sized to match standard ISO files and gutta-percha points. M-series pluggers and spreaders The ISO-sizing and tapering virtually eliminate binding and allow deeper penetration for better apical seal. These patented instruments are ergonomically balanced for easy manipulation of curved canals. The ISO color-coded instruments are available in either a single-ended or double-ended spreader/plugger combination.