Grindbeck manufactures Readymade Rubber and Plain Cork Gasket. Grindbeck has received ISO 9001:2000 certifications. Readymade Rubber and Plain Cork Gasket have natural cork granules uniformity which is dispersed throughout and cork has unique characteristics. Readymade Rubber and Plain Cork Gasket is making of cells with walls of a strong resinous substance that is flexible but will not stretch. Readymade Rubber and Plain Cork Gasket is trapped inside each cell is a pocket of air; in fact cork is 90% air [by volume]. Under pressure the air inside the gasket is squeezed into a smaller space but because the cell is airtight, the compressed air maintains counter pressure until the force is released.