As a result of using these bearings, I found that they are high-quality and perfect for my industrial needs. The shielded design ensures that no dirt or debris gets into the bearings, ensuring a longer lifespan. The 5X11X4mm size is ideal for various applications .The only downside is that they are a bit pricey compared to other options in the market. However, the quality and durability MAKE them worth the investment. I highly recommend these bearings for anyone in the industrial and scientific field..