Fuse & Polyswitch Question

In a crossover, Can a 12V 27W "courtesy lamp" type fuse be replaced with a 12v 5W or 12V 10W?
This is what the courtesy lamp style fuse looks like http://www.germansupply.com/home/image.php?productid=16964
I can't find the 12V 27W anywhere.


What type of Polyswitch would I use to replace the 12V 27W fuse? Thanks!