Made of a heat-, non-stick silicone material our socks repel build-up of molten plastic. This really helps with sticky materials like co-polyesters and filled-composite materials that like to build up on nozzles. Very useful silicone socks: keep your heater block clean and free from burnt and blackened plastic. They don't just keep the block clean, but also keep heat inside the hotend and off your print. Helps to keep the hotend temperature extremely stable, particularly if you use high-airflow cooling around the nozzle to cool the print. The covers simply push onto the front of the Hot End with no disassembly - they be a tight fit when first pushed on cold. When hot the silicone expand to the correct size to fit the hotend snugly. Please kindly note: we suggest highest safe temperature resistance is about 230 Celsius-250 Celsius/ 446 Fahrenheit-482 Fahrenheit. Item Type: Heated Block Model Number: sock for MK10 block colour: blue Material:Silicone Rubber Package Contents: 15 * Socks 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.