1. Manufacturer & Internal Design: The core differences stem from variations in the internal ceramic material formulation, electrode structure, and manufacturing processes between the two suppliers. This may lead to subtle variances in parameters not explicitly stated in the datasheets, such as: Start-up Time & Drive Level Characteristics: The ECS component may exhibit slightly different start-up speed or minimum drive power requirements, which warrants attention in ultra-low-power designs (e.g., battery-powered systems). Harmonic Content & Phase Noise: Differences in internal construction can affect output spectral purity. This may be a consideration in high-speed digital circuits or RF applications sensitive to clock jitter, though its impact is typically negligible for general-purpose microcontroller clocking. Long-term Aging & Reliability: Different materials and processes result in potential variations in the frequency drift rate over time (aging rate) and reliability performance under temperature cycling. Verification is recommended for products requiring extremely long lifespan or operation in harsh environments. 2. Price & Supply Chain: The ECS part is significantly lower in cost (approximately 30.6% lower), primarily reflecting differences in brand premium, production costs, and market strategy. Selecting the ECS component can reduce BOM cost, but its supply stability, lifecycle, and manufacturer support should be evaluated against the project's long-term requirements. Recommendation: Direct substitution is acceptable for general-purpose applications such as consumer electronics and industrial controls. For applications involving RF, precision timing, or ultra-high reliability requirements, it is advisable to conduct functional and stress testing (e.g., temperature cycling, extended operation) on the actual circuit board, particularly within the target MCU's oscillator circuit, to verify compatibility and long-term stability.