Magnetische roerder, 2000 ml stille magnetische mixer met verwarmingsplaat, LED-verwarmingsindicator, efficiënte warmtegeleiding Draagbare kookplaat magnetische roerder voor laboratorium(EU)

The heating function is extremely poor!A 1000 ml glass beaker was filled with 200 ml water, a magnet bar, and placed on the stirrer, heat was activated (there's only an on/off switch, and no temp regulator), and the spinning rate was moderate. After over 1 hour the water temp was only 58 C. I then tried 2 others of the same stirrers, and the result was the same - the water temp never got warmer than 55 - 60 degrees Celsius.

The knob extends above the surface limiting the size of the vessel.