I bought the IO toothbrush as a present for my husband. We have always shared our electric toothbrush so it was disappointing that there was only 1 head with an expensive present. I therefore had to order extra heads to be able to share again. There were no instructions with the toothbrush, only pictures, so I have no idea what the different colours mean!

I have been using the iO for a few months now and its so much improved over the previous 9000 model I was using. I find the tooth brush heads are way in front of any competitor although the cost I feel is expensive.