Right - there is one. The Scott Cornwall "Foil effects cap".
It is a really good quality cap that comes with a very detailed book. The cap can be reused many times.
The beauty of the cap is that you can do something called "true toning". You pull hair through the cap (there are many different ways of doing this - you can mark out a "map" on the cap according to the books instructions for a t-section, fine foils, slices, etc etc depending what you want). With a normal kit you would apply bleach to the hair, and leave it on till it is the desired colour but - this can be scary, sometimes you don't really know how it will look against your hair. The beauty of this kit is that you can wash the bleach off once you've reached say a canary yellow, then dry it off with the cap still on, and apply a semi permenant colour to "tone" the highlights to your desired shade.
This means if you want blonde highlights but you want a really ashy blonde to blend with the tones of your natural hair, you can get the shade really right.
Even better, if you have dyed brown hair and want red highlights, or copper, or mahogany, or deep caramel, you bleach up the highlights first, rinse, then apply your semi or permenant colour on top, leave for the allocated time then rinse off.
It takes away a lot of the guess work - when you are actually sitting there doing it, its really hard to know when to take off the bleach. Also, you are sitting there watching it rapidly go orange then yellow etc you can easily freak out, but when you know you are doing "true toning" you don't - you just rinse it off when its light blonde, knowing you are going to tone the colour to the correct colour with a semi or permenant.
Does that make sense?