28592 Features: -Engraving tool.-1 diamond bit with spherical head size: 0.78".-Carves finest details in glass, metal, wood, and plastic.-Engraves for hours without fatigue.-High speed.-Easy use and simple push-in/pull-out shaft holder.-Easy control and light-weight.-Recommended use with NG2/S and NG 5/E power supply units. Dimensions: -Overall dimensions: 1.18" H x 7.28" W x 6.49" D, 0.5 lbs. Warranty: -Manufacturer provides 2 year limited warranty.