Casio(R) SL-300 Handheld Solar Display Calculator

Back in 1983 (if you can believe it), I bought a used Casio SL-300 in a suburban garage sale... I had never heard of, nor seen, a solar powered anything... I thought it was miraculous! Those were the days of big lunky Texas Instrument units that took batteries. Today, I was just doing a search to see if I could find the original on the internet, and I see they're still making it, with only minor design modifications.

I still have it, and it still works. How can I ever get rid of it? I swear, this is the most reliable electronic gadget I've ever seen. Can you believe a 20 year old solar calculator still works? Shocking!