StackMat timer
A StackMat timer is a timer designed for use in sport stacking and speedcubing. StackMat timers have two touch pads, one on each side of the display. The hands are placed on the two touch pads. After a brief delay of 0.55 seconds, a green light will light up. This indicates the timer is ready and the user can proceed at his discretion — when one or both of the hands are released from the touch pads, the timer begins. The timer stops when both hands are placed back on the touch pads, at which point the timer stops and displays a time with accuracy to either 0.01 or 0.001 seconds, depending on the version of the timer. Generation 3 and newer timers can resolve milliseconds (three decimal digits) while older timers only resolve to hundredths of a second (two decimal digits).
The StackMat timer is sometimes included with a mat that is made of neoprene, the same material commonly used in mouse pads. Some timers also glow in the dark. Others have a data port that allow it to be connected to an external display to allow for an audience to watch the timer in real time. In competitions for both speedcubing and speedstacking the use of stackmat timers are required. The timers are placed on a connected to timer displays.