I have two Femto-Tech CRM-510 continuous Radon monitors for sale. I bought them around 2 years ago for $4,000 each. They are due for calibration February 16, 2019. Asking $1500 each for them. They hook to the computer and you download the test for building the PDF, Word Doc, etc formats for the Radon reports. Comes with Pelican case too. I’ve ran many reports with them, and they’ve been a solid money maker.