A concrete cover is essentially a spacer that is used to lift the rebar matrix off the ground so that concrete may flow underneath the rebar. In order to prevent corrosion of the rebar, it needs to be fully embedded in concrete. It protects the Reinforcement from Environment exposure or Corrosion. Give reinforcing bars sufficient embedding to enable them to be stressed without slipping. There are different types of Concrete Covers.
Wired Covers:

In these types of covers the thickness is fixed as per the requirement like 20mm, 25mm, 30mm, 40mm, and 50mm as per the requirement and design. A wire is given on the top surface to tie the cover block with a reinforcement bar.

Non-wired Covers:

These covers are similar to wired covers the main difference is here instead of wire a U shape space is provided on the top surface to place the reinforcement bar and it is also available in various sizes like 30 mm, 40mm, 50mm, 60mm, 70mm as per the requirement and design.

Flexi Covers:

These covers are the updated version of non-wired covers here the cover is made in such a way that it has multiple sizes in one design. Like 20mm, 25mm, 30mm and 40mm are combined in one piece on different surfaces. So It can be used as per the requirement and design. Also, a hole is given in the center to tie the wire for use in columns and beams for side spacing.

Circular Covers:

These are special purpose covers mainly it is used in circular RCC casting works like Piles, Columns, and others where the outer surface is in a circular shape. It is also available in various sizes like 40mm, 50mm, 75mm as per requirement and design. Also here a hole is given to pass the reinforcement rod from it.