Power levels
The number of power levels (adjustments) provided in the device.
The more levels provided in the design (with the same maximum power) — the more precisely you can adjust the heating to your preferences. On the other hand, the abundance of adjustments affects the complexity and price of the device, despite the fact that there is not always a need for this. So, for electric sheets (see "Type"),
2 – 3 modes are quite enough — intensive for preheating and one, less often two workers. On the other hand, the opposite situation occurs —
6 or even more power levels.
Power consumption
Rated power consumed by the heater during operation.
Technically, other things being equal, a more powerful device will heat up faster and heat more greatly, but its energy consumption will also be higher. However, in fact, this parameter is of secondary importance: manufacturers select power in such a way as to provide the heating pad with the necessary performance. So paying attention to power makes sense mainly when comparing and only in cases where the differences are significant — for example, if one model consumes 100 W, and another of similar size only 60 W.
Cable length
The length of the cable for connecting to the mains, which is equipped with a heating pad.
On the one hand, the longer the wire, the easier it is to connect the device to the outlet, the lower the chance that an extension cord will be needed for this. On the other hand, a long cable can get tangled and create inconvenience. Thus, in most heating pads, the length of the wire is about 2 – 2.5 m — a longer length is rarely required and in such cases it is usually not a problem to find an extension cord.