Just purchased this sensor assuming it would work with my existing Oregon Scientific Base station and another one I just ordered.Unfortunately this particular sensor (also sensors THR138 and THN138) only work with older base stations running the "1.0" protocol (newer units run "2.1"). Here is the list of base stations listed at the Oregon Scientific site that support this older sensor:BA928 BAR338PA BAR888NA EMR812 JMR828 JMR838WF JTR168LR RMR112So only order this sensor product if you have one of the above product numbers listed on your base station (unless you just want to use this as a standalone temperature sensor)The Oregon Scientific web site has a complete list in a PDF file as far as which sensors are supported by the various base base stations, so if you aren't sure, check out their site before ordering an additional sensor for your base station.