I had a fantastic drug free natural birth and I found the Labour TENS to be a great help in achieving this goal. 

I spent the first 3 hours of my labour just using the Labour TENS and a stress ball to count through each contraction.

I arrived at hospital at 7pm with contractions 2 minutes apart and was 9cm dilated.  My Doctor broke my waters and as the pain increased I used stamping and vocalisation along with the TENS to control the pain.  After half an hour I was pushing and my baby girl was delivered 20 minutes later, a healthy 4kg! 

I think the Labour TENS helped me conserve energy in the early part of my labour so I had plenty of energy to stay active during the most difficult part.