This classification covers crystal oscillators, ceramic resonators, and resonant circuit modules used for generating reference clock signals in manufacturing equipment and control systems. These components are utilized in timing control for NC machine tools, synchronization signals for PLCs, reference frequencies for measuring instruments, clock generation for communication equipment, and control circuits for industrial robots. Includes crystal oscillators (XO), voltage-controlled crystal oscillators (VCXO), temperature-compensated crystal oscillators (TCXO), ceramic resonators, SAW resonators, LC resonant circuits, and RC oscillators. Covers a comprehensive range of oscillation and resonance components necessary for electronic control in manufacturing environments, from industrial-grade products with high-precision frequency stability and temperature characteristics to general-purpose products.