Modify PistolFollow

Ok...I've been trying to figure out how to use my Modify Pistol skill, but I haven't had any luck. When I use the skill it tell me that I don't have the proper component. Can anyone tell me which components to purchase?

Thanks. I forgot to update this post as I found out from a Master Smuugler in game...
Do you know at what point you get this component?

Rancor pet- 100mil
treasure map- 1mil
500 restuss coms- 5mil
finding a master smuggler in game- priceless


Edited, Mar 15th 2008 8:04pm by Jerok