Bosch 18636-01 36V Litheon Hammer Drill with 1-L and 1-XL Battery Unibody Powertrain - keeps gearing in alignment for the most durable drive train on the market Seel Reinforced Collar - Provides enhanced durability when dropped on the chuck Durashield Housing - Constructed to withstand real world conditions. Withstands repeated 1-story drops when the competition fails easily Accessible Brushes - Quick maintenenance to minimize downtime Ratcheting Single Sleeve 1/2" Chuck - Carbide tipped jaws have stronger bit retention