Hybrid Crystal Resonator SMD Crystals Murata Hybrid Crystal Resonators (HCR) Surface-Mount Device (SMD) Crystals are small, cost-effective crystals that feature improved accuracy of less than ±100ppm. This is achieved through a quartz crystal element encased in Murata's proven packaging derived from its ceramic resonator technology. This combination creates a timing device that is smaller and lower cost than standard quartz crystals while maintaining the precision of quartz. Murata HCR SMD Crystals are RoHS compliant.