It’s 1 second window. In this mode the pedal is constantly recording to a 1 second buffer in the background. When you press Touch the 4 read heads start playing back the loop. Keep in mind that there are 2 ways to use the Touch footswitch though - either held down for momentary effects, or with a quick tap to engage / disengage.
Currently if a loop is playing back and you want to get new material into the buffer you have to tap Touch to stop the loop and then tap again to start playing back a new one. This can lead to a short gap between loops which may be undesirable. In the next update I’ll be making this smoother with “double buffering” so that you can record a new loop while the current one is playing back. There’s a little more info / context in this thread.