Made of SUS304 stainless steel, so it will not rust even when used outdoors, and it has a diameter of 0.2 inches (5.5 mm), so it wont break even when using it hard. Drilling holes are required when used with hardwood materials. 1 box (100 pieces) *Includes 1 square bit (#2) Color: Brown; Screw size: Φ0.2 x 1.8 inches (5.5 x 45 mm); Optimal hole drill diameter: 0.18 inches (4.5 mm).