The Panasonic DY-WL5 is a Wireless LAN Adapter to add wireless network functions to your Panasonic Home Theater sets, Blu-Ray Players, Viera TVs etc. If you are looking for the Panasonic DY-WL5 alternative or equivalent, you would be pleased to know that I managed to use a cheap 3rd party WLAN adapter instead.
I wasn’t going to shell out 30-50 dollars for a wireless adapter. From Wikidevi, the Panasonic DY-WL5 was listed as a Ralink chipset with an RT5370 chip. That’s quite a common chipset and it’s manufactured by Foxconn as T77H350 (OEM reference model). There are at least 50 known RT5370 models and they should work with your Panasonic device. I used this particular RT5370 USB which I bought from Aliexpress a few years ago. It was automatically detected by the SC-BTT433 and was able to connect to a WPA2 network. Since these devices are basically running on a Linux variant, they would be equipped with the necessary chipset drivers, as long as it is not a unique variant, there’s a good chance a 3rd party chip would work.
Similarly, you can search for another Panasonic WLAN adapter, the DY_WL10, which runs on a BCM4323 chip.