Hello Matias,

You will have to use the Tobii Gaze SDK for this, but support for this in the Tobii EyeX SDK is coming.
Below you will find the source code to a console application that will output the information you want.

//-----------------------------------------------------------------------
// Copyright 2014 Tobii Technology AB. All rights reserved.
//-----------------------------------------------------------------------

using System;
using System.Threading;
using Tobii.Gaze.Core;

namespace EyeTrackerInfo
{
    public sealed class Program
    {
        public static void Main(string[] args)
        {
            Thread eventLoopThread = null;
            EyeTracker tracker = null;

            try
            {
                // Get the connected eye tracker.
                tracker = GetConnectedEyeTracker();

                // Create and run the eye tracker event loop.
                eventLoopThread = CreateAndRunEventLoopThread(tracker);

                // Connect to the eye tracker.
                tracker.Connect();

                // Get tracker information.
                var info = tracker.GetDeviceInfo();

                // Print information to the console.
                Console.WriteLine("Eye tracker model: {0}", info.Model);
                Console.WriteLine("Eye tracker serial number: {0}", info.SerialNumber);
                Console.WriteLine("Firmware version: {0}", info.FirmwareVersion);
            }
            finally
            {
                if (eventLoopThread != null)
                {
                    tracker.BreakEventLoop();                 
                    eventLoopThread.Join();
                }

                if (tracker != null)
                {
                    tracker.Dispose();
                }
            }

            Console.WriteLine();
            Console.WriteLine("Press ANY key to quit");
            Console.ReadKey(true);  
        }

        private static EyeTracker GetConnectedEyeTracker()
        {
            // Get the URL to the eye tracker.
            var url = new EyeTrackerCoreLibrary().GetConnectedEyeTracker();

            // Create a new eye tracker using the URL.
            return new EyeTracker(url);
        }

        private static Thread CreateAndRunEventLoopThread(IEyeTracker tracker)
        {
            var thread = new Thread(() =>
            {
                try
                {
                    tracker.RunEventLoop();
                }
                catch (EyeTrackerException ex)
                {
                    Console.WriteLine("An error occurred in the eye tracker event loop: " + ex.Message);
                }
            });
            thread.Start();
            return thread;
        }
    }
}