I'm a fan of collars by Cae. I think these may be among the most wearable collars in SL ever. All of her jewelry is beautifully understated and blends well with most outfits.
About a year ago Cae has closed her in-world shop, but kept her collection available on SL Marketplace. Cae also kept a small skybox, where customers could claim redelivery. Via redelivery you can swap your Peanut scripted Cae collar for a new N° 9 Series 500 Full Version free of charge.
This offer may no longer be available past June 2022, meaning that if you want a N° 9 Full Version for your Cae collar, you should claim redelivery from the terminal in Cae's skybox at your earliest convenience.
When redelivery becomes unavailable, you will still be able to download updates for your N° 9 Series 500 scripted Cae collar at the Temple of the Collar, but not for the Peanut scripted ones.
To download an update for your N° 9 Series 500 collar, teleport to Temple of the Collar, open your collar's menu, select About, click Update and accept the inventory offer from the update server.
To claim redelivery for your Peanut scripted collar, teleport to Cae's skybox and use the terminal.