DK-REFILL #101, 7/16", 1/2" Drill Stop Collar Kit DK-Refill kit contains 7 set screw collars to fit drill sizes: 1/8", 3/16", 1/4", 5/16", 3/8", 7/16" and 1/2". Refill kit comes packaged in a sealed bag, hex keys are not included in this kit.