DO NOT buy the pens! Instead buy yourself a high quality paint and micro touch up sticks, they are extremely small and precise and an excellent choice for highly detailed paint touch ups.
You will need: 2oz paint, 2oz clear coat and the mircro dabbers.
Here is the link for the paint:
Touch Up Paint and Accessories | AutomotiveTouchup
Here is the link for the touch up micro dabbers
Microdabbers Touch up Applicators | Body and Bumper | AutomotiveTouchup
My sincere advice is to stay away from the pens. The pens are almost always way to big to use on a practical sized scratch or chip. The end result will leave you will a line of paint twice the size of your chip or scratch. Furthermore they are hard to control and you either have too little paint on the pen or entirely too much paint on the pen. They are JUNK! The 2oz jars also include brushes but don't use them either they are just as bad as the pens. Stick to the dabbers your paint job will thank you.
I have personally used this website and paint and stand behind them 100%. the paint is same quality as factory.