Product review (1 stars): I am pretty sure the are a generic foot for this application ...
Bought for my 2 year old Viking dual fuel range.  They arrived fast... but were not a suitable replacement.  I am pretty sure the are a generic foot for this application and not specifically intended for Viking ranges.  It seems after reading the reviews the people that had success with them had other brands for stoves.  They fit into the holes in the grates...but their circumference is much smaller than the OEM feet. But most importantly they are not tall enough to keep the grate from coming in contact with the stove top surface to prevent scratching.  I called Viking and they happily shipped me some replacements for free...Viking obviously sells just the feet...so you don't have to buy the whole grate as some suggested in other reviews.  Do not buy if you have a Viking!