I've used Knight Hot Shot nipples going back more years than I can remember. Never have I had a misfire w/knight installed. But than again. I can say the same for those few mixed bag of Standard nipples I've tried also. A salesperson at G/Mtn as I recall said Knight H/Shots were better than all the rest marketed. To this day I have yet to doubt that salespersons bold claim. Spare nipples. Boy do I have em. Over the years I've squirreld away so many K/H/S/Nipples. I have no recourse but!!~ too use them.