These little things keep your A/C & Heating system running, they are called "Run Capacitors." They are at the bottom of the totem pole in complexity, size and cost, but they are near the top of the totem pole as a cause for A/C emergency repair calls! They keep the big things running like motors and compressors. That is why Alpha Air Conditioning checks their performance at every "Precision Tune-up." Have you called for your tune-up yet?