Four models for electrically driven drawworks of AC variable frequency are at your option:JC40DB JC50DB;JC70DB; JC90DB Drawworks are single drum structure. Main brake is hydraulic disc brake. Brake disc is water-cooled or air-cooled. Auxiliary brake is motor dynamic brake, magnetic eddy current brake (water-cooled or air-cooled) or EATON brake. Equipped with automatic driller according to customers` requirements