As a hesitant buyer in the Industrial and Scientific world, I was pleasantly surprised with this product. My analysis of this bi-metal strength mandrel showed that it is sturdy and durable, and can easily drill a clean hole in drywall. It fits perfectly with the hole saw and is easy to use. The only con I could think of is that it is a bit more expensive than other mandrels on the market. Overall, I highly recommend this product for anyone who needs a reliable cutting tool.