Adapter for hole saw ideal for enlarging existing holes by allowing two hole saws to be mounted on the chuck at the same time. Compatible with all HSS dual-metal hole saws from the BizLine range.- The solution for enlarging existing holes by simultaneously mounting two hole saws on the chuck- Compatible with all BIZLINE bi-metal HSS hole saws.- Remove the centering drill and mount the largest hole saw on the arbor.- Screw the corresponding size hole saw into the existing hole on the adapter.