Plasplugs Solid Wall Super Grips are suitable for fixing into concrete and brick. They are available in 3 different sizes/colours. Yellow Regular-duty, accepts screws No.4-8 (3-4.5mm) Red Regular-duty, accepts screws No.6-12 (3.5-5.5mm) Brown Heavy-duty, accepts screws No.8-14 (4.5-7mm) The brown wall plugs are heavy-duty and will accept screws No 8-14 (4.5-7mm). Drill 7mm. Pack quantity 300.