This is Alfa Laval Pneumatic Torque Wrench / Torque Multiplier - Model CLS 2/100 45-13209
Made in Germany by alki TECHNIK GmbH for Alfa Laval
It's NOT a normal impact wrench. It's a high-precision pneumatic torque wrench.
What is it use for?
For tightening and loosening very big bolts with exact force (torque) - especially on Alfa Laval machines.
Alfa Laval makes big industrial machines - Decanter Centrifuges, Separators, Heat Exchangers, Dairy / Brewery / Oil & Gas plants.