Micrometers are instruments for precision dimensional gaging consisting of a ground spindle and anvil mounted in a C-shaped steel frame.  Noncontact laser micrometers are also available

Dimensional gages and instruments provide quantitative measurements of product or component dimensional and form attributes such as wall thickness, depth, height, length, inner diameter (ID), outer diameter (OD), taper or bore.

Depth gages are used to measure of the depth of holes, cavities, or other component features.

Calipers typically use a precise slide movement for inside, outside, depth or step measurements. Some caliper types are used for comparing or transferring dimensions.

Height gages are used for measuring the height of components or product features.

Thread gages are dimensional instruments for measuring and/or verifying thread size, pitch or other parameters.

Bore and ID gages are designed for internal diameter dimensional measurement or assessment.

Thickness gages are used to make precise dimensional measurements on a wide variety of coatings and materials including steel, plastic, glass, rubber, ceramics, paint, electroplated layers, enamels, etc

Snap gages are used in production settings where specific diametrical or thickness measurements must be repeated frequently with precision and accuracy.

Air gages use pneumatic pressure and flow to measure or sort dimensional attributes.

Optical comparators are instruments that project a magnified image or profile of a part onto a screen for comparison to a standard overlay profile or scale. 

Hall effect proximity sensors are used to detect the proximity, presence or absence of a magnetic object using a critical distance.

Laser micrometers measure extremely small distances using laser technology

Compact disk-read only memory (CD-ROM) refers to a 4.75-inch, laser encoded, optical memory storage medium. Technologies include CD-ROM XA (extended architecture), CD-RW (rewritable), and CD-WO (write once

Rotary positioning stages are devices with tables or shafts that may be rotated to any angular position. They may be driven or simple slides.