Model: ST-DH Gear Ratio: 1:1 Maximum Motor Speed: 40,000 rpm Total Length: 84 mm Weight: 72 g 2.53 oz Ion Plating Treatment: Yes Spray Holes: 1 Chuck: Mechanical Lock Acceptable Burs (ISO 1791): Shaft Type 2 (HP) Connections: ISO 11498 and ISO 3964 connections