As long as the item is available, you will be able to add it to your cart.
If you see that the status of an item is “Out of Stock”, it means that it’s currently in somebody else’s shopping cart. Items can be reserved in your shopping cart for 120 minutes.
For items that are sold out, status will be reflected as “Out of Stock”. However occasionally, you will be able to select on the sizes which available to be made-to order.