United Abrasives- SAIT 45140 Tungsten Carbide Heavy Duty Die Grinder Bur SF3 3/8" x 3/4" x 1/4" Tungsten Carbide construcion for long life and durability High Quality Manufacturing method delivers vibratin free operation Precision ground with diamond wheels to produce a very sharp uniform cutting edge Each enclosed in individual plastic capsules for storage and protection Excellent for confined or hard to reach areas