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.