I've been on here before but had to re-register since the new bbs...
I'm curious to know - what were you searching for exactly when you found these pipes please?
These pipes are are extremely hard to find. I happen to have a rusting 4 into 1 that looks just like this. It's beautiful with it's slight rise and Yoshi can! I looked for months in the US for one of these a year or so ago and couldn't find anything unless you custom ordered. If it's for an early 90's 400 Katana I'd say you would have a good chance it should fit, but I'm NOT an expert...
I may look at one of these myself this summer. I don't think I could stand going back to the stock can now. I'll let you know if I do.