Connor-Winfield VCXOs have become the benchmark for quality, tight tolerance, low jitter, and high frequency performance. We use only fundamental mode crystals, produced and quality controlled at our own facility. The results are superior jitter and phase noise performance. For high frequency applications we manufacture and employ a special inverted mesa crystal design. The crystal is precisely etched so that only the active center is thin while the outer perimeter remains thicker and very stable to allow mechanical handling. The result is a highly reliable, high frequency fundamental mode crystal.