I lost one I had because the pipe rusted and it fell off. I want to find some that don't weld on so it is easier to remove them next time the exhaust gets replaced. The current one(s) were welded on. I pulled the other tip off some my truck doesn't look like crap with one tip. It was about to fall off also. Here are some more specs.

2.5 or 2.25 inlet
Prefer 45˚ slash. 15 will work if 45 can't be found.
Has to be 4"
I prefer 18" long but 12 will work if 18 can't be found.

I might just cut off the pipe behind the muffler for now since it will probably be a PITA to find a place that will do custom work over here.

 

summitracing.com has some inexpensive polished stainless tips. All kinds of sizes and lengths. They are Summit brand tips. I'm gonna buy one for my truck. I've had one of those tips before and they look good.

 

Magnaflow #35147 @ Big Exhaust.