High quality optocoupler relays typically have the following characteristics:

1. Stable isolation performance: It can effectively isolate input and output to prevent interference and electrical noise.

2. High transmission rate: Fast signal transmission, capable of switching from input to output in a short period of time.

3. Low input-output delay: able to quickly respond to input signals and activate outputs in the shortest possible time.

4. High voltage resistance: able to withstand higher voltages, providing a larger operating range and stability.

5. Low pulse width distortion: Minimize pulse width distortion during signal transmission to maintain signal accuracy.

6. Low distortion and low noise: Maintain the clarity of the signal during transmission, avoiding distortion and noise interference.

7. Long lifespan and reliability: The quality of components and materials, as well as manufacturing processes, determine their lifespan and reliability.

8. Wide temperature range: able to work stably in different temperature environments and adapt to various application scenarios.

9. Small volume: With a compact design, it is suitable for applications with limited space.

10. Compliance with safety standards: Comply with relevant safety certifications and standards to ensure the safety and compliance of the product.

In summary, high-quality optocoupler relays should have stable isolation performance, high transmission rate, low latency, high voltage resistance, low distortion and noise, and long lifespan.