Not good at all. Firstly, despite what it says on the box and above, neither my Iphone 4 nor the I trip app recogises this device. Secondly the transmitter is very poor. I had a Kensington FM transmitter supporting my IPod classic and rarely had to change channel and certainly never during my journey to work . With this I have to rescan 2-3 times during the journey to work. Lastly, there is no retaining clip. It constantly falls out of the IPhone. To be frank this product is quite dangerous as it requires inordinate self discipline not to rescan or reinsert it in to the iphone whilst driving.Avoid