Feature: 1. EFFECTIVE PREVENT SCALDING: Silicone sock heater block cover can effectively keep heating block and nozzle around clean, which has a certain role in preventing burns 2. HEAT RESISTANT MATERIAL: Heater block cover is made of heat resistant silicone, which is not adhered to other printing materials and easy to tidy up 3. THERMAL INSULATION: The thermal insulation sleeve has good thermal insulation characteristics, which can effectively keep the temperature of the heating block stable, especially if the printing head is equipped with a model cooling fan for cooling printing, which can effectively keep the temperature of the heating block from being affected by the surrounding wind, and improve the printing quality 4. APPLICABLE MATERIALS: Heater block silicone cover has better temperature resistant and longer service life, supporting the use of PLA, ABS, TPU, HIPS, WOOD, PETG and other materials 5. ELASTIC AND NON SLIP: 3D printer heater block silicone cover has good elasticity, can be installed more closely with the heating block, and is not easy to fall off 6. APPLICABLE MODEL: Heater block cover is compatible with for Prusa MK3.9, for Prusa MK4, for Prusa XL and does not work with the original for prusa I3, MK2, MK2.5, MK3, MK3S, MK3S+ Mini Specification: Item Type: Silicone Sock Heater Block Cover Material: Silicone Product Size: Approx. 24 x 16 x 15mm / 0.94 x 0.63 x 0.59in Temperature Resistor: 280℃ Function: Prevent hot, protect the heating block Color: Black. Package List: 3 x Silicone Sock Heater Block Cover