There are 50 pieces of trays. Must take all together. Price is fixed. Using tin trays reduces the smell of pigeon droppings. Droppings dry quickly. No worms in the droppings.
Plastic trays available in the market are made of very low-quality plastic. Using these trays creates gas which is harmful to pigeons and makes them sick.
That is why professional farmers have fewer sick pigeons because they use tin trays.