Cool. Remember, if they don't have what you want, from what I see, they will custom manufacture it for you.
Problem with me was this:
https://www.houseoftelephones.com/cord-handset-cloth-spade-spade-black-4-conductor.html If you know the 500 series WE, you'll know that cord won't work, as the speaker in the handset is like another 8 inches away, and those cords wouldn't be long enough on the speaker wire. So, I asked for a special cord, extra 3 dollars, and they are custom manufacturing one for me that has the speaker wire elongated for the 500 series handset.
