An improved structure industrial computer consisting of a system case, with the system case having a flexible component fastened along the edge at one side and a frame member also fastened to the flexible component. Preferred tertiary-heteroalkylamine compounds are substituted N,N-bis-phenyl aminoalcohols. The upper and lower legs have a pitch angle locking system for adjustably changing the pitch angle of the desk top using manually operated stoppers connected to the lower legs that engage notches on the curved upper legs for locking the desktop in place. The clamping device includes a clamping assembly which is useable to hold the register elements in place.