The high-flow (HF) model comes with all the great features of the original March pump - magnetic drive, handles flow restriction, okay for boiling temperatures, 6' cord with plug, food-grade materials in contact with the liquid, 1/2" ports, etc. - but now features a different slightly higher flow rate with less issues of cavitation.
7.2 GPM High Temp (Max 250F) - Magnetic Drive
The magnetic drive in a March pump acts as a clutch allowing the user to put back pressure on the pump to slow down flow. Since it is magnetic drive, it is not self-priming, you must put the pump under the level of the liquid source.