WMF21 series thermistors are used to limit the inrush current in the power supply circuit of various types of power supplies, / CFL etc. and the heating circuit of CRT in color TV / monitor, heaters, filaments etc. WMF21 series thermistors are of the wired and resin coated type, it has the characteristics of small size, high power, strong inrush current limiting, fast response, high reliability etc. The temperature decreases as the thermistors' material (B) increases and the resistance at the end decreases. The higher the heat capacity, the stronger the ability to limit the inrush current. It is directly proportional to the product of the thermal time constant (T) and the thermal dissipation constant (d). WMF21 series thermistors have such a wide range of applications, mainly used in switching power supplies, UPS power supplies, CFL, power supply circuits etc. Color: black material: metal package contents: 1 * thermistor Note: Light and different displays may cause the color of the item in the picture to be slightly different from the real thing. The allowed measurement error is +/- 1-3 cm.