This is one of our most highly recommended bearings. It is ideal for heavy loads and long service life in extremely dirty environments including foundries and concrete plants. Testing has shown this bearing to last up to 7 times longer than its semi-precision equivalent. Metal shields deflect large particle debris and protect a rubber contact seal that is very effective against fine dust and other small particle debris. The seals add rotational drag and are not recommended for gravity applications with light product. Recommended for powered applications where roller resistance is not an issue and the roller is constantly rotating.