These MasonMate Loose Bolt Shield Anchors have the following specifications: Size: M6. Anchor Hole Size: 12mm. Shield Length: 45mm. Thread Diameter: 6mm. Fastens up to: 40mm. Bolt Length: 85mm. Min. Hole Depth: 50mm. Qty. Per Box: 50. The MasonMate Loose Bolt Shield Anchors are for use in most types of masonry or concrete. Zinc plated for increased durability. M6 x 40mm (50)