Based on my observations, the United Abrasives SAIT 71225 Encore 10 Pack is not worth the investment. The abrasive brushes lacked durability and had a short lifespan, which is unacceptable for an industrial and scientific product. The bristles fell apart quickly and didn't provide the expected level of performance. The only positive aspect was the packaging that kept the brushes secure. However, that's hardly enough to justify purchasing these brushes. Overall, I would not recommend this product.