PACE CLOCK / SHOT CLOCK-By Colorado Time Systems. Four large 10" LED digits allows synchronization of multiple pace clocks. Basic Pace Clock can be run as a stand alone unit, or set to run in a series of pace clocks. The clock operates, with or without a timer or controller. Displays minutes and seconds up to 59:59 and rolls over to 00:00. Pace Clock/Shot Clock includes water polo shot clock functionality with battery and horn. Requires use of System 5 or System 6 timing system. 110 volt/60HZ, with rechargeable internal battery, will run more than 6 hours before recharging.