The model of the Signal Sustain is similar to that of the Signal Delay, but has a different button function and the black bar is smooth. The button function can be found by hovering the cursor over the button on the machine.
This item acts similar to the Signal Delay. The main difference is that while the Signal Delay makes the beginning of the signal delayed, the Signal Sustain immediately starts the signal.
When supplied by power through a Wire, the Signal Sustain will immediately supply power to its output, but when the supplied power is removed, the Signal Sustain will wait a certain amount of time before turning the output power off. The duration is indicated by the position of the white arrow along the black bar. Pressing the button will make the arrow go up slightly, increasing the duration. When the arrow reaches the top, it resets to the bottom. This functionality can be used to make automatic wood cutters.