Made of high quality heat silicone. Ensures your 3D printer's hot end stays clean and running efficiently, improving hot end temperature stability. Enhanced Stability: Designed to maintain a stable hot end temperature, these silicone sleeves prevent the filament from sticking to the heater block or nozzle This ensures smoother printing and less maintenance. Perfect for long-term printing. Excellent heat resistance: Made of silicone, can withstand temperatures up to 280C For temperatures above this threshold, simply remove the silicone sleeve to prevent damage, ensuring safe and effective 3D printing Colour: Material:Silicone Package Contents: 20 * 3d printer accessories 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.