This impact wrench is a perfect companion when you take on your building project. Since it runs on compressed air, you get a more constant power than with a battery.
From Autodoc
HAZET 9012SPC Impact wrench 550 6,3 92,1 127,4 7000
Conrad Electronic
Hazet 9012SPC 9012SPC Pneumatic impact driver Tool holder: 1/2 (12.5 mm) male square Torque (max.): 850 Nm