With use of PTC element,PTC cartridge heater is advantaged: 

The heater can only reach a set maximum element temperature

No thermal over-temperature sensing device is needed.

No extra wires to connect or safety systems to calibrate.

They limit their output, rather than overheating and burning out as traditional heaters do.
Easy Installation and Maintenance

Heaters are available in 304, 316stainless, copper, aluminium to handle a wide range of chemical compatibility requirements.
Diameter: 12,15,18,21 mm
Length     50 mm to 1400 mm

Power max. 1500 W

Connection: screw plug,Optional  Wiring, vulcanized connection

Application:

Household applications:
Travel irons, hotplates, water evaporators, espresso and coffee machines, Towel rails etc

Industrial applications:
Oil preheating, frost protection, valve heating, mould heating,laminating equipment, glue gun, printing equipment etc.