It is named "Bi-Metal Heatbreak". The bi-metal heatbreak melts filament faster and excellent heat insulation effect for 3D printer. The wonderful workmanship will ensure its high performance as excellent 3D printer accessory. We use a special process to hold them firmly together. You don't need to worry about it being damaged. Features - Color: As shown. - Material: Bi-metal. - Size: 2.10X0.70X0.70 cm/0.83X0.28X0.28 inch. - Made by material, safe and , which could be used for very long time. - Adopts precision production to increase and ensure the stable characteristics and high reliability. - Heat-resistant, , to withstand wear and damage, excellent and reliable. - It is simple and unique in design, but it's practical to use, which will give you fantastic use experience. - Great and wonderful printing parts to build 3D printer or used as replacement for old or broken part. Package list: 2 x Heatbreaks