The Milwaukee Quik-Lok 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. The reusable pin adapter is compatible with hole saws from 1-1/4" up to 6-7/8" without the risk of thread stripping or binding and retains hole enlargement capability for 1-1/4"+ hole saws. The small thread adapter is intended for hole saws from 9/16" to 1-3/16". The large thread adapter is intended for hole saws from 1-1/4" up to 2".