Heat management design, you have to know the

  The thermal conductivity of different materials is altered, which is related to the structure, density, humidity, temperature, pressure

and so on. W / Mk is the unit of thermal conductivity, which means Watt / (m * Kelvin), also known as "K".

  The comparison of thermal conductivity can be evaluated in terms of K value. The K value, or thermal conductivity, is the speed of thermal conductivity of a 

uniform material. If a material is valued of K of 1, it means that a material of 1 cubic meter will transfer heat at the rate of 1 Watt when the temperature 

difference on the opposite side is 1 degree. K is 1W / Mk. The lower the value, the less heat the material  will transfer.

  This value can be useful in selecting heat transfer materials, such as attaching a radiator to a material, or as a selection condition for a

heating pad.