The Model 1027 CRM is rugged, easy to use, and less expensive than its' competitors. The technology employed in the Model 1027 has been used commercially since 1986, when it was first introduced as the Model 1022, At Ease Professional Radon Tester. The Sun Nuclear Corporation, Model 1027 Professional Continuous Radon Monitor is classified as a Continuous Radon Monitor (CRM) testing device, and has been evaluated and accepted by the US EPA for use in real estate transaction testing.