Select Disctinct using Linq

EF - Linq

// Make sure you use DTO and not EF Poco 
// Else you will get error 

public List<Models.PostalCode> SearchCity(string searchTerm)
        {
            try
            {
                using (var db = new PmsContext())
                {
                    var pa = db.PostalCodes.Distinct().Where(x => x.town.Contains(searchTerm)).ToList();

                    List<Models.PostalCode> cities = (from p in db.PostalCodes
                             where p.town.Contains(searchTerm)
                             select new Models.PostalCode()
                             {
                                 town = p.town,
                             }
                            ).Distinct().ToList();

                 //   return db.PostalCodes.Where(x => x.town.Contains(searchTerm)).Distinct().ToList();

                    return cities; 

                }
            }
            catch (Exception ex)
            {

            }

            return new List<Models.PostalCode>();

        }