4PCS Official Creality 3D Printer Hotend Silicone Sock Heater Block Silicone Cover for Ender 3/Ender 3 Pro/Ender 3 V2/Ender 5 Pro/CR-10 10S S4 S5

"4PCS Comgrow Printer Hotend Silicone Sock Heater Block Silicone Cover for Ender 3 / Ender 3 Pro / Ender 3 S1 / Ender 5 CR-10 10S S4 S5.

It will keep your heater block clean and free from burnt and blackened plastic.

They don't just keep the block clean, but also keep heat inside the hotend and off your print."