public class TipoCustom
{
   public TipoCustom(string p1, string p2)
   {
      prop1 = p1;
      prop2 = p2;
   }

   private strnig prop1;
   private strnig Prop1
   {
      get {return prop1;}
      set {prop1 = value;}
   }

   private strnig prop2;
   private strnig Prop2
   {
      get {return prop2;}
      set {prop2 = value;}
   }
}

List<TipoCustom> lista = new List<TipoCustom>();

lista.Add(new TipoCustom("primo valore", "secondo valore"));