Vendor for HVAC control cable slip? See photo

Same clip found on plenum and many controllers. I've shipped them at "parts wanted" before. I don't have any more but... that where others got them.
For the record... many years ago I had one jump off the plenum and disappear. I had to go to a parts yard to get one. Some time later I had the instrument panel out and found that clip on the dash speaker magnet.