Temperature Compensated Crystal Oscillator (TCXO) in a ceramic package with a metal lid. Frequency Parameters Frequency 13.0MHz to 52.0MHz Frequency Tolerance ±2.00ppm Tolerance Condition @ 25°C, 1hr after reflow. Frequency Stability ±0.50ppm to ±2.00ppm Ageing ±1ppm max 1st year @ 25°C. .