The MILWAUKEE QUIK-LOK 49-56-7555 Arbor Set provides a universal fit with all industry standard threaded hole saw sizes and offers the fastest hole saw changes. The included adapters ensure compatibility with small-thread and large-hole saws and eliminate the need for multiple arbors, saving you time and money. Our QUIK-LOK system is designed with the ultimate durability to deliver the strength and reliability to match the all-day demands of the job site. Due to the threaded design, this system retains Hole Enlargement capability.