Cycle World write-up on them.
Allan N. Lader of Gresham, Oregon, applied for the patent on Snuff-or-Nots on November 5, 1964, and got the patent on October 10, 1967. A computer programmer back when computers understood Fortran and took up entire climate-controlled rooms, Lader was also a keen on-and-off-road rider who disliked having to put in and take out exhaust baffles—or what he calls “snuffers”—on his four-stroke dual-purpose bikes for different riding environments.
There were shops back in the day that wouldn’t even work on a bike with Snuff-or-Nots. Joe Bolger, legendary AMA Hall-of-Fame scrambles and MX racer, inventor and former Honda shop owner, reminded me of this when I asked him if he’d ever installed any. On the other hand, Carl Cranke, another AMA Hall-of-Fame member told me that when he worked at and raced for a Honda shop, he installed what seemed like thousands of them.
I love the way a pile of crap that laid around in a storage shed for 40 years can result in a little snapshot of motorcycle history.