Replacement high-temperature silicone sock for the Phaetus Dragon SF/HF heater block. This black heater-block cover insulates the hotend, helps keep nozzle temperature steadier, and reduces melted-filament buildup on compatible Dragon hotends. Why use it Cleaner hotend maintenance: silicone helps keep stray filament off the heater block and nozzle area. More stable heat: insulating the block reduces heat loss so the hotend can hold temperature more consistently. Drop-in spare: shaped for Phaetus Dragon SF/HF-style heater blocks; keep one on hand before the original sock tears or carbonizes. Specifications Brand: Phaetus Product: Dragon silicone heater-block sock Fitment: Phaetus Dragon SF/HF hotends Material: high-temperature silicone Color: black Quantity: 1 sock Fitment notes Use this for the standard Dragon SF/HF block shape, not Dragonfly, Rapido, UHF, or other hotend blocks. Pairs with compatible V6-style nozzles such as the Phaetus Brass V6 Style Nozzle, Phaetus Copper Plated V6 Style Nozzle, and Phaetus Hardened Steel V6 Style Nozzle. Do not rely on the sock to make an incorrectly assembled hotend safe; verify heater, thermistor, and PID tuning after replacement.