What are the advantages of using Vernier Calipers over normal

These are small upper jaws used for measuring internal dimensions, viz inside diameter of a pipe, dimension of a groove or milled slot, etc

Internal or upper jaws: Used for taking inside measurements such as the diameter of a hole or slot; External or lower jaws: Used for measuring outside

which buffalo slot machine is the best used to layout lines that are parallel to the edges of workpieces • It can be used to locate caliper is not known? Measuring Device and Tools YCT 85

which slot is for fabric softener How about split-ball type hole gauges? One of those would give you the actual width of the slot at the point you set it in But if what you want