Abstract: A cassette or box for containing and holding a planar substrate such as a reticle having a clamp bar coupled to corner supports by a spring or flexure and a linkage. A clamp bar is pivotally attached to bottom corner supports and a spring or flexure and linked to a top corner support, such that movement of the load bar causes the corner supports to pivot away from a reticle being held only at the corners. An elevation bar is also used to preposition the reticle in one direction. The present invention greatly facilitates the positioning and handling of a reticle as used in photolithography to manufacture semiconductor devices. Additionally, the present invention greatly reduces particulate contamination.