The cord can be used with any club in the bag although I used a driver in this video to demonstrate how using the cord will help you rotate more efficiently and sweep the ball off the tee.
This is a great training aid to use for your irons too, particularly if your divots are too deep. When using the cord with irons, I recommend using a 7 iron and tee the ball up about 1/2". Perform the drill as described with the driver and you should start "clipping" the ball off the tee with your 7 iron.
