Colorado Time Systems PC-PORTABLE Portable Pace Clock/Shot Clock, these units can be run as standalone pace clocks, or set to run in a series of pace clocks with or without a timer or controller. Every pace clock in a series displays the same information. Or use the PC Portable version of the Basic Pace Clock for Water Polo Shot Clock functionality. Shot clocks must be connected to the timer. Additional clocks can be added to display game time, time out time, and team scores.