A centralizing device is configured to centralize/decentralize an associated tool in a well. The centralizing device includes a body that extends along a longitudinal axis X, the body having a bore that extends from one end to another end of the body; a first piston shaped as a cylinder and provided around a central portion of the body; a second piston shaped as a cylinder and provided around the central portion of the body; a bridge provided around the central portion of the body, between the first and second pistons; and a pair of arms, each arm being attached with one end to a corresponding one of the first and second pistons and with another end to each other. The second piston, the bridge, and the central portion of the body define a sealed chamber, which is sealed from the ambient.