Great, but be aware of these things..........
we bought this for our weimeraner as she needs lots of exercise and it has been a great success. Only a couple of points, she is still able to pull with it - especially if she sees another dog/animal so you need to be aware of that. Also even though we tied the lead cord in a knot she was supposed to be unable to pull open, it did so very quickly. We remedied this by attaching a short lead and this works well. Also worth pointing out is to check your bike before purchasing, as this doesn't fit all modern bikes- you need a good length of upright bar under the saddle to fix it to.