Abstract: A circularly configured rotatable element rotationally mounted for use in a drafting, drawing, tracing or light tabletops of generally rectangular or square configuration, a concave-convex annular interface disposed between the circular element and the adjacent portion of the tabletop and a series of 360.degree. sockets or apertures arranged along the interface for receiving a locking spring pin element therein. Also, indicia displaying 360.degree. markings may be disposed about peripheral portions of the circular element. A swivel assembly such as used in a lazy susan is used to support the rotatable element. In one embodiment, the circular element is constructed of transparent, translucent or similar material with a set of at least a pair of fluorescent lights mounted thereunder. In another embodiment, the rotatable element is in the form of an opaque, light impervious circular element.