Came across these on Ebay today. Never heard of them before. Did a little more research and found a couple other articles. Interesting stuff...guy who invented them seemed like a rad dude.

https://www.ebay.com/itm/Vintage-Ski...IAAOSwqrVcaf-O

https://www.wildsnow.com/8181/miller...-earl-history/

https://www.deseretnews.com/article/...stry-dies.html