Calculates pitch speed from 20 to 99 MPH. The virtual umpire calls balls, strikes, outs and walks. Electronics simulate an at-bat or half-inning (one or two players). The software records total pitch count, strikes balls, outs and walks. Maintains and automatically scrolls stats for one or two players. Long battery life--electronics run from 80 to 100 hours on 4 D-cells. Heavy-duty 16 gauge steel frame with collapsible hinge.