Click on the image to go to the web page with the online metronome on at metronomeonline.com.
Once your there just click on the number of beats per minute, make sure your speakers are turned on and away you go.
Working with a metronome is really important as you develop your accuracy and timing with your guitar practise. Whether it’s running through some scales of working on a new performance piece give it a go. It can be very frustrating initially as the metronome is very unforgiving but this practise will pay off as your guitar playing progresses.