CLOVER-Stacking Patchwork Pins. Each of these steel straight pins has a diameter of 0.5mm; a length of 36mm; and heat resistant glass heads-- great for a variety of sewing projects. They come in a slim clear plastic case that can be securely stacked with other cases to create one compact unit. This package contains twenty pins and one stackable container. Container measures 2-1/2 inches long with a 5/8 inch diameter. Imported.