IconSize.cs

using System.Collections.Generic;

namespace ReplaceIcon
{
    public class IconSize
    {
        public string Size { get; private set; }

        public List<string> Related { get; private set; } // e.g. 16 and 16x16, 32 and 32x32, scalable

        public IconSize(string size)
        {
            Size = size;

            Related = new List<string>() { size };
        }

        public IconSize(string size, params string[] related)
            : this(size)
        {
            Related.AddRange(related);
        }
    }
}