Here's a previously owned estate find and it looks like someone marked R1 and R2 on the units. The TRENDnet 200 Mbps Powerline AV Adapter Kit, model TPL-303E2K, is a set of wall plug in adapters designed for powerline networking in homes or offices. With a maximum powerline data rate of 200 Mbps, this kit allows for reliable internet connections via powerline cables. The TRENDnet brand is known for producing quality networking products. Sold "as is".