Ael crystals hc 49u quartz crystal resonators through hole ael x10m000000l023 a 10000000mhz crystal resonator with a tolerance of 20ppm in a hc 49u style holder that is suitable for a wide range of frequency control applications and serves as direct replacement for existing designs ael x10m000000l023 100mhz 20ppm hc49u quartz crystal resonator