Compatible devices link on Buy page broken

On https://www.xfinity.com/buy/customize-internet-equipment in the section "No, I'll use my own modem and router", the link "Check for compatible devices" - https://www.xfinity.com/buy/undefined - goes to a 404 page: https://www.xfinity.com/error/404

This is an obvious programming error, because the "compatible devices" web page shouldn't have "undefined" in its path unless nobody actually defined it.

So... what's the correct path?

Also, please tell someone at Comcast/Xfinity to fix it. There's no reason not to have that functional unless Xfinity was intentionally subverting our right to not lease devices we don't have adequate transparency on and don't need to spend extraneous money on with costly features we mostly don't need.