Plugging it in makes a beep, all indicators light up, and then it turns off.
On its screen, it has orange numbers (1-6) for temperature and blue numbers (30-60-90) for operating time. Pressing ON always opens it at temperature 1 and for a duration of 90.
NEGATIVE: It does not retain the last temperature and duration settings you input.
POSITIVE: As time passes, the display changes from 90 to 60, then to 30, and then it turns off.
I noticed on a consumption meter that the temperature is adjusted by turning the power on and off to the heating element. This means that the scale of 1-6 for temperature does not correspond to lower operating wattage, but to less operating time. The heating pad operates at 102W. POSITIVE: It seems that once it reaches the desired temperature, it turns on and off to maintain it. This means it operates more frequently at 6 than at 3. At 6, it operates for 10 seconds and turns off for about 25-30 seconds. On a lower scale, it remains on for shorter intervals and less frequently. This means energy savings because the heating pad is not continuously on for a long time, only for as long as it needs to maintain its temperature. In contrast to most cheap heating pads that remain on and consume energy until you turn them off. The only NEGATIVE, as I mentioned, is that it does not "remember" the last setting. I needed this feature to plug it into a smart outlet and have it operate for more than 90 minutes during the night. Also, its buttons are not proportional, and when it is plugged in, it is turned off.

My daughter enjoyed it throughout the winter. Much better than a heating pad. For cold feet and a sensitive tummy. We also warmed her bed with it, but we unplugged it before she went to sleep, for better or for worse.