From the Manufacturer:
RX-090 is replacement receiver for the ET-300 mini and ET-400 educator and the ET-900 Easy Educator.
RX-120 is replacement receiver for the ET-800, UL-1200 and WF-1200.
THIS IS A NON-RETURNABLE PRODUCT
Manufacturer's warranty info can be found here: https://www.ecollar.com/pages/warranty-returns-and-cancellation
