www.DataSheet4U.com ATSM-49 and SX2050 Surface Mount Crystals SX2050-R 00.0000 MHz (customer specified) (-R signifies RoHS compliant part) ATSM-49-R 00.0000 MHz (customer specified) (-R signifies RoHS compliant part) Notes: Series resonant designated by “SR” prefix (i.e., SRATSM-49 or SRSX2050). Because this product is based on AT-strip technology, not all frequencies in the range stated are available. Contact the factory for availability of specific frequencies. ATSM-49 BT cut f.