Purchased new on Fleabay for 70GBP.

http://www.ebay.com/itm/BMW-K-100-1982-1992-HIGH-PERFORMANCE-SILICONE-RADIATOR-HOSES-BLACK-/162433688232?epid=1971451060&hash=item25d1cd62a8:g:VFgAAOSwEOxXQE5N&vxp=mtr


Recently got a leaking coolant hose behind the radiator of my 86 K100 so I decided just to replace all of them since they're all 30 years old. And buying these was cheaper than buying a set of new ones from The Fatherland.

They all fit perfectly except the one that attaches to the filler cap.  The angle of it was a few degrees off but it was still quite usable.

I recommend them and would buy them again. (Except I probably won't be around 30 years from now.)

I don't have a dyno available to see how "high performance" they are but I'm sure they add lots of horsepower.

I replaced mine with BMW parts. Honestly, though, they didn't look or feel like they needed it at all.  If I'd known about this option three weeks ago...