Bock Reciprocating piston compressors are divided into two types: open type and semi-hermetic type, the open compressors for external drive (via V-belt or clutch). Force transmission is by a form-fitting shaft connection. Nearly all drive-related requirements are possible. This type of compressor design is very compact, robust and easy to handle, naturally with oil pump lubrication. The semi-hermetic type compressors are for inside motor drive and the motor is built-in the compressor, it consist of the efficiency and reliability on the highest level of quality.