Self-drilling point, zinc-plated drywall screws, 4.2 x 65, supplied in a box of 1000. Drywall screws are commonly used for fixing plasterboard. The self-drilling point cuts its own hole as the screw is driven in, which saves time on repeated fixing, and the zinc-plated finish gives some protection against corrosion in dry interior conditions. A box of 1000 suits larger jobs and repeat use. Check the screw length against the thickness of the materials you are fixing, and use the correct driver bit for the screw head.