Made of Aluminum and silica gel material, durable These heating blocks are CNC machined, with high precision and quality, and stable performance Extend the life of the heater block and extruder by keeping it cleane The Silicone cover will keep your heater block clean and repel plastic of burnt, blackened, and build-up The structure of the silicone sock prevents heat from escaping quickly, and helps stabilize the temperature of the heating block Heat Break Thread: M6 Length: 27mm Diameter: 7mm Bore: 4.1mm Used with 2 x 4mm bowden tubing straight-through nozzle, keep the 3D printer working stable, work as the stock heat break. Gold Heater Block Hole for throat tube set screw: M6 Hole for heater/thermistor set screw: M3 Heating tube mounting hole: 6mm diameter The heater block of holes is the right size and in the right . Compatibility: The 3D printer parts fit for 3, 3 Pro, 3 V2, 5, 5 Pro, -10, -10S. Easy to install, work great replacement, and work as the stock for 3 hotend. Using Note: If your print head temperature is above 250 degrees for a long time, please remove your silicone sleeve. Long-term temperature above 250 degrees will damage the silicone sleeve. Material: Aluminum+silica gel colour: Gold+black Package Contents: 3 Set Heater Block Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.