Abstract: A fluid operated device comprising an elongated housing defining an elongated interior cylinder and an elongated slot formed along one side of the housing and open to the cylinder. A piston is longitudinally, slidably mounted in the cylinder and forms a first chamber in the cylinder between one end of the housing and one end of the piston and a second chamber between the other end of the housing and the other end of the piston. Fluid seals are provided around each end of the piston. In addition, an elongated band constructed of a magnetic material is secured within the cylinder and is of sufficient width so that the band covers the housing slot. A pair of elongated flexible magnets are secured to the housing along the slot to magnetically attract the band against the housing and thus sealingly close the housing slot along the cylinder chambers.