4star doublelayer dustproof cover prevents dust from entering the bearing, helping to protect internal components and extend service life. Selflubricating bearing with an oiling hole; the bearing is factoryfilled with the proper amount of lubricant. No cleaning or prelubrication is required before installation. Lubricant can be replenished after about six months. If you do not plan to replenish, close the cover to maintain protection. The bearing housing is heavyduty, providing greater durability than ordinary bearing housings. Use scenarios: In dusty production lines or conveyors where dust protection is essential to prolong bearing life. In automated machinery or gearboxes where reduced maintenance downtime is desired due to factory lubrication and long intervals. In outdoor or harsh industrial environments where a robust, durable housing helps withstand demanding operating conditions. Notes on specifications: Function: dust protection, selflubrication, easy maintenance with optional replenishment. Compatibility, size, and material details are not specified here; refer to the product datasheet for exact dimensions and compatibility with your bearing configurations. Performance: designed for durability and extended service life in demanding environments.