The Yato YT-70890 countertop joint template is designed for use with a router to mill joints on countertops. It works with the milling machine using a 30 mm diameter guide bushing (i.e., a guide ring) and a finger cutter with a diameter of 12.7 mm. The template is made of MDF, which enhances its durability. Using the template ensures that the countertops are securely mounted.