using System;

using System.Collections.Generic;

​

namespace CustomCollection

{

    class Machine

    {

        public string Brand { get; set; }

        /// <summary>

        /// Speed of the machine in RPM 

        /// </summary>

        public int Speed { get; set; }

​

        public override string ToString()

        {

            return String.Format("(Brand:{0}, Speed:{1}rpm)", this.Brand, this.Speed);

        }

    }

​

    class Program

    {

        static void Main(string[] args)

        {

            List<Machine> machines = new List<Machine>

            {

                new Machine{Brand = "Fehlmann", Speed = 100},

                new Machine{Brand = "Hedelius", Speed = 5000},

                new Machine{Brand = "Kondia", Speed = 1000},

                new Machine{Brand = "Mikron", Speed = 2000},

                new Machine{Brand = "Okuma", Speed = 10},

            };

​

            var fastMachines = machines.Where(s => s.Speed >= 500);

            foreach (var machine in fastMachines)

            {

                Console.WriteLine(machine);

            }

        }

    }

}

​