Rubi Tools 04911 Drill Bit Features: -Dry Cutting Diamond Drill Bits. -For the Drilling of ceramic tiles and porcelain tiles. -Only to be used with grinder. -Operational speed between 10000 and 14000 rpm. -Finish with M14 thread. -The Drilling guide is a system for guiding dry cutting, diamond Drill bits. -Vacuum fixation. -Adjustable from Ø 20 mm to 90 mm. -For use with grinder. -The kit is made of foragers centering guide. -Ø 20 mm, 28 mm, 35 mm, 43 mm, 50 mm, 60 mm and 65 mm dry cutting diamond Drill bits. -With case. -Available in 3/4" (20 mm), 1 1/8" (28 mm, 1 3/8" (35 mm), 1 3/4" (43 mm), 2" (50 mm), 2 1/4" (60 mm),and 2 1/2" (65 mm). Size: 2-1/4" (60 mm)