4 Piece Long Reach Carbide Burr Set - Unique 6" long reach 1/4" Dia. shanks allow you to reach deep into cylinder heads or other cast iron and steel parts. Precision ground and heat treated for long life and vibration free use. Includes 3/8" ball, 3/8"x 3/4" cylinder, 3/8"x 3/4" tree and 1/2"x 1" tree