Description: Stainless Steel Clam Shell Vent Marine Grade, Mirror Surface Polished UV and weather resistant and great for routing cables, wire, etc. Dimension: approx. 4 x 4.5cm / 1.57 x 1.77 inch Hole Diameter: approx. 3mm / 0.12 inch Color: Silver Package Includes: 1 Piece Clam Shell Vent