C# Welcher Datentyp oder was ist das?

private void AddBuffer(byte b)

{

    buffer.Add(b);

    byte[] msg =  buffer.ToArray();

    //Make sure that the message integrity is correct

    if (this.CheckDataIntegrity(msg))

    {

        if (DataReceived != null)

        {

            ModbusEventArgs args = new ModbusEventArgs();

            GetValue(msg, args);

            DataReceived(this, args);

        }

        buffer.RemoveRange(0, buffer.Count);

    }

}