Manual cold storage board, also known as manual hook insulation board, is the main type of PU insulation board before the large-scale popularity of machine-made boards.  The product is made of double-sided galvanized color steel plate core polyurethane (can also be replaced with rock wool), good thermal insulation effect. 

The hook is a significant external feature of this type of product, relying on the hook can be more tightly combined, and removable.  All the basic properties of the product can be customized to meet your individual use needs.