Prusa INDuction Autoleveling probe, is a vital component facilitating the calibration of our printers. There are 2 different versions: V1, used in MK2/S, and V2, used on MK2.5, MK2.5S, MK3, and MK3S. The difference is that the V2 has an inbuilt thermistor to compensate for the difference in cold and hot measurements. V1 and V2 are not interchangeable.