Hi Dan, the latest version is 4.0.58. Feel free to email Lorin Stieff directly at: lcstieffatradelecdotcom . He would be happy to send the info over to you, I'm sure.

Good Morning George,
I just wanted to mention, and I am sure that all participants on this forum would agree, that this is the PERFECT time for you to consider becoming a licensed, certified radon measurement or mitigation professional. It is a fantastic add-on to your business, and will allow you to better serve your clients, in the long run. Visit https://nrpp.info/ for more information on this. Good for you for being concerned and aware about high levels of radon!