Auto_Scale
It gets the scale of your object in system unit and rescale it . For example if I have a head modell that has a width of 1.55 cm (incorrect) and I want it to be 20 cm without try and error then I use Auto Scale
Installation / Usage:
1-Uncompress the Auto_Scale.zip in 3d Studio max main folder
2-Start 3d max
3-choose customize user interface.... from Customize menu
4-Choose Toolbar tab
5-under WorldofPolygons Category Choose Auto_Scale and add it to your toolbar