Alpha Numeric code generator

using System;
using System.Collections.Generic;

public class Program
{
    static Random random = new Random();
    public static List<char> charList = new List<char> {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
                                                        'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
                                                        'U', 'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3',
                                                        '4', '5', '6', '7', '8', '9'};

    public static void Main()
    {
        //Display output of 10 random codes
        for(int i = 0; i <10; i++)
        {
            DisplayCode(GetCode());
        }

    }

    // Generate random 16 char string from the charList list
    public static string GetCode()
    {
        string output = "";

        for(int i = 0; i<16; i++)
        {
            int charIndex = random.Next(charList.Count);
            output += charList[charIndex];
        }

        return output;
    }

    // Format string with "-" every 4 chars
    public static void DisplayCode(string code)
    {
        code = code.Insert(12,"-");
        code = code.Insert(8,"-");
        code = code.Insert(4,"-");

        Console.WriteLine(code);
    }
}