The product shown in the image is a sheet of self-adhesive white dots, which are typically sold as adhesive cover caps or double-sided tape stickers. 
Type: These are small, circular, self-adhesive dots on a backing sheet.
Material and Use: They can be made of PVC or other materials and are commonly used to cover screw heads on furniture. Alternatively, they may be double-sided adhesive dots used for various mounting applications. 
Features: The adhesive backing provides a strong bond to surfaces. They are designed for easy application by simply peeling them off the sheet and pressing them into place. 
Color: The product in the image is white.