Here is a pic I took recently to show the difference between a Seiko OEM Fat bar, a ToxicFATTIES and a ToxicSLIMfat. The Fat bars are excellent bars until you have to remove them. Then they will piss you off in a just a few seconds. We eliminated this stress with our ToxicFATTIES since they are the same quality and diameter but they have double flanges for easy removal. Now our ToxicSLIMfat's take this one step further, they have the same double flanges, Seiko bar end diameter and they are slim in the middle. They are made specifically for straps/bracelets that normally won't fit with the stock bars.
So check them out and if you have any questions them send them my way.