For determining the correct force pack to use, the decision point between the standard force pack and the low force pack is based on the neck tension that the neck has been sized for. The typical rule of thumb for the use of the low force pack is neck tensions of .0015-.002” or less. The scale on the low force pack is 0-50lbs. Therefore, when seating with light neck tensions you will have better resolution for lower force readings.
The standard force pack range is 0-150 lbs which will accommodate pretty much any neck tension.
The Low Force Pack is only compatible with the K&M Modified Dial Indicator (D150)