Magento 2 Quantity Dropdown extension changes quantity box from input box into dropdown list so that customers only can choose from dropdown quantity list to add product to cart.Main features of this extension:
Customers are able to choose quantity from a dropdown list
Can apply product quantity increment for the list.
Admin can add custom value to the list.
Product price will be shown in quantity dropdown list.
Quantity which is higher than stock will be hidden.
Work in product page, product list page and wishlist page.
Can configure to display quantity for a specific product or every products.