The new CM-S44 power units are used on all GPA hydropneumatic presses and take advantage of the following features: - high speed and low air consumption in the approach and return stroke with total length up to 200 mm in the "U" versions, - working stroke up to 30 mm, with progressive application of power using the pressure intensifier hydraulic circuit, - enclosed oil tank (A) in line with the pneumatic and hydraulic stages, with reduced side dimensions and with high operation speed (up to 100 cycles/1' in the 20 kN models), - patented hydraulic circuit which allows air bleeding in the higher point (B) for a better venting of air bubbles after maintenance, - possibility of working in any position thanks to the oil tank with pneumatic spring (C), - cylinders with hard anodised aluminium pipes allowing a high level of protection against oxidation and high pneumatic performances, - reduced consumption of tools and dies, - reduced noise level, - reduced maintenance requirements.