Mechanisms are provided for controlling a fidelity of a simulation of a system. The tape cartridge accommodates a reel hub unit rotatably, for winding a tape on its periphery, and includes a leader member for holding and fixing a leading edge of the tape. A support member engages the pressure transfer member when the force development device exerts a predetermined force against the shower wall. The diffusion-symmetric slant reflectors has a variety of shapes, including conical, elliptical cone longitudinal prismatic or other polyhedron shapes. The balls enter the side funnels of the upper member and are collected on the angled feeder tray.