I carried an SL-20 from 1979-2011, when I retired. During that time I went thru 4 batteries, 5 bulbs and one switch. At one point I had two of them because I was working a very isolated area. I lost my original one about six years ago, but my other one that I bought in 1982 is still going strong. When the Stinger first came out, I got one of those to keep on my belt as a backup.
The SL-20 also makes a great impact weapon when needed. More than one way to make a dirtbag see the light.
Great flashlights in my opinion.
If You Heard The Shot, You Weren't The Target