A device for sealing a space between two adjacent surfaces comprises a seal holder, a flexible thin sheet-like member folded back on itself forming a deformed cylinder having a generally tear-drop shaped cross section, the two ends of the folded back sheet-like member being held and retained in close proximity by the seal holder to maintain the tear-drop shaped cross section with the seal holder being mounted on one surface relative to the other surface such that a portion of the deformed cylinder forms at least a line contact seal engagement with that surface. In a preferred embodiment, the two ends of the folded back sheet-like member have end portions folded over in the same direction, one nesting inside the other forming an acute angle with an adjacent portion of the deformed cylinder with the width of the outermost folded end portion being greater than the width of the innermost folded portion thereby providing an achoring hook for supporting engagement with the seal holder wherein the innermost folded end portion is permitted to move axially relative to the outermost folded end portion to maintain line contact sealing engagement with the surface. The seal holder includes a groove-like chamber for supporting the seal anchoring hook, a narrow insertion slot and a hook retaining lip. In a preferred application, a sealing device is used in sealing a developer and/or cleaner housing in eletrostatographic reproducing apparatus.