Genuine Creality 3D® Ender 3 CR-10 3-Pack Hotend Silicon Sock
These were sourced directly from Creality in Shenzhen China. This silicon sock is compatible with both the Ender 3-series and CR-10 series.
2021-04-12: I got another shipment today and this offered a chance to show you that they really are "genuine" Creality parts. I added an image to this listing showing a desktop full of packaged silicon socks and laying on the floor too. I remove each and every one and throw the package away. I mean hundreds of packages. If you look closely those packages are deforming the silicon sock and if I left it in there it would soon be worthless because it will no longer fit your hotend because it will never regain it's proper shape or dimensions. I have asked Creality to stop packaging them this way but they have not responded.