Pin type insulator is the type of insulator which is secured to the cross arm on the pole. It is a low voltage insulator.

How Pin Insulator Looks

The figure below displays a pin type insulator.

On top of the insulator, there is a groove for housing the conductor.

The figure below displays 2-d side view of above insulator:

Practical Applications of Pin Insulator

Pin type insulator is practically employed in power transmission and distribution systems having voltages below 33 kV.

The figure below displays PIN insulator connected on a pylon:

Photo from Types of Insulators Book

The transmission line conductor passes through the groove (See 2d-image shown previously) and is tied to the insulator using wire.