Features: Brand new and high quality Good thermal stability, high temperature and low temperature resistance; They also provide a huge increase in temperature stability, especially if you use high airflow cooling around the nozzle to cool the print. These covers keep your nozzle clean and free from burnt, blackened plastic. Toughness and elasticity are very good and will not be deformed due to external force; Used for heat blocks of 3D printer extruder, high temperature resistance of 280 ℃. Package Includes: 5 x Silicone Cover for Heat Block Specifications: Item Type: Heated Block Silicone Cover Model: MK8 Heat Block Silicone Cover Application: For Sidewinder X1 & for Genius Heated Block Material: Silicone Color: Blue Size: 23 x 19 mm/ 0.91 x 0.75 inches (approx) Note: Due to problems with lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to manual measurement.