Detects radon gas from 3 months to 1 year Pro-Lab's Long-Term Radon Test Kit for a 3 to 12-month time period provides a more accurate reading of radon gas since radon emissions tend to come at different times of the year. Use the short-term Pro-Lab Radon Gas Test Kit first; if radon is detected, then use this test to confirm. Simply place the black radon detector in an undisturbed area for 3 to 12 months. Once the long-term test is complete, seal the detector with the enclosed cap, fill out the data card and return to Pro–Lab in the pre–paid envelope. Professional laboratory test results will arrive within two weeks; then you can make any changes necessary to protect you and your family from further exposure. A Radon in Water Test Kit is also available. [tabs] Why We Like It If you suspect radon, or your short-term test comes in positive, then this is the best way to really know whether radon is a problem in your home or office. It's easy, safe, quick and inexpensive, and it produces reliable and professional results. Features & benefits Easy-to-use – includes clearly laid out step-by-step instructions Accurate – provides laboratory testing for thorough and conclusive results ALERT: If you're a New Jersey resident, there's a $10 fee for the New Jersey Department of Environmental Protection Agency's administrative costs. When sending in your detector, please include a $10 check made out to Pro-Lab to cover this fee.