Orbit 67215 1/2 GPH Inline Dripper

Hey there! Thank you for your query on the Milwaukee 49-56-9647 hole saw. You will need a diamond or carbide grit hole saw, which Milwaukee, unfortunately, does not offer in a 4-1/8in or 4-1/4in size. There are other brands that offer such hole saws, but for us to ensure we can provide you with a compatible attachment, it would be best to give us the brand, model number, and/or photos of your drill. Feel free to send them to one of our knowledgeable customer support specialists via email at support@plumbersstock.com. They will be happy to assist you further. Thank you for visiting PlumbersStock. Have a great day!