Here is the difference between the Hydrofarm, Ranco, and Johnson thermostats.
The Hydrofarm is designed for heat mats used in horticulture applications, which are comparable in wattage and temperatures, to the Under Tank Heaters used in reptile applications.
The Ranco and Johnson thermostats are designed for commercial heating and air-conditioning applications, which is why they have such a high power handling capability, and are more expensive. It just so happens that they are easily adapted to run reptile heating sources, and space heaters, if you have a dedicated reptile room.