Ensure it is rated for your local grid, typically 50/60Hz . Where to Buy

You can use a capacitor with a voltage rating that is the same or higher than your original. If you have a 370V capacitor, a 440V replacement is acceptable and may actually last longer.

This must match the original exactly. For example, if your label says 45+5 µF , you need a dual-run capacitor with those specific ratings for the compressor and fan.

Sites like Amazon offer a wide variety of "universal" and brand-specific options.