The electronic part 49S-9.81563-20-10-10/B with DIP Crystal resonators 49S RoHS is a type of crystal resonator manufactured by Liming. It is a very small, low-power device that is commonly used in crystal oscillator circuits. It has a 4-pin dual in-line package (DIP) configuration, with two signal pins, two ground pins, and two enable pins, which can be used to control the operation of the circuit. The frequency of the device is 9.81563MHz, and it is RoHS compliant, meaning that it eliminates hazardous materials from its construction and operation. It is meant for use in indoor environments, as it must be kept away from moisture and humidity.