Capacitor Vents

Capacitor vents are intentional weak points built into larger capacitors to prevent the capacitors from causing serious personal injury when exploding. While these vents are present on all newer capacitors of a certain size, they may not be present on older capacitors.

Capacitor vents are different shapes for different brands of capacitors. You may be able to tell the brand of capacitor by looking at the shape of the vent. Keep in mind that the vent shape is not a clear indicator of a certain brand or capacitor; cheap capacitors will often steal vent shapes from more well-known capacitor manufacturers and some brand will use multiple vent shapes depending on the age and/or series of the capacitor.