I know the Ti end caps are different in that they have a "Ti" logo embossed on the side and I do believe they are made of titanium. I just weighed mine (not from a P3 but both are from 2.5 versions but I bet there comparable ideas with a slightly different design). The Ti cap weighs 12.25 grams and the regular weighs 21.41 grams.That's a dern good question. Mine is stealth coated and never bothered to look. Unfortunately, I'm on a lil vacation and that mod did not come with....
Whether you need one is a different story, they will both work fine. But now if you just want one....