Metal 10-Frame metal bound queen excluder fits standard hives. Electrically welded, precisely spaced metal wires make up the grid system. This wire grid is edged (bound) with metal on all edges. Plastic The new & improved plastic queen excluder is all plastic with properly sized openings for the worker bees to travel through. Flexible and durable. Easy to clean, corrosion proof. Ship wt. 8 oz.