Thermal performance is the primary consideration when choosing a clip. The thermal resistance of interface materials is inversely proportional to the clip force, in general the higher the clip force, the better the performance. Keep in mind that the characteristics of interface materials vary greatly and high clip forces are not always necessary. For example, low force clips are more than adequate in applications using thermal grease or phase change materials because those materials 'wet' the surface under low pressure. However, high force clips may be necessary when using a silicone based insulator to achieve adequate performance. Besides different clip forces, Max Clips are available in different lengths. The clip should contact the center of the device to ensure pressure is distributed evenly across the interface, therefore the length of the clip determines the mounting location. The standard length clip is designed to fit most applications. Aavid also offers short and long clip options which will allow the device to be mounted higher or lower on the heatsink if needed.