Using playerprefs to save level progression

Ok, so I use this code public static readonly int NUMBER_OF_LEVELS = 12; public static bool[] finishedLevels = new bool[NUMBER_OF_LEVELS]; And I need to save this bool because the level selection menu checks if the bool equals true( at the end of each level it makes that level's number equal true) So how would i go abouts using player prefs to save the data.