The seal is a material or a part that prevents fluid or solid particles from leaking from adjacent joint faces and prevents intrusion of external impurities such as dust and moisture into parts inside the machine. The factors affecting the performance of various seals are different. For example, mechanical seals (filler seals, etc.) have factors such as temperature, medium, wear and pressure. Use classification 1. Classification by function: divided into shaft seal, hole seal, dust seal, guide ring, fixed seal, rotary seal; 2. Classified by material: divided into rubber, polyurethane, engineering plastics, etc. Mini Measuring Tape,Mini Tape Measure,Small Tape Measure,Mini Retractable Tape Measure SHANGQIU CHAOYUE MEASURING TOOLS CO., LTD , https://www.calibrateds.com