The adjustable shelves on these welded mesh security carts can be set at a range of heights or removed altogether to accommodate objects of different sizes. The carts have two doors with latches or hasps that can be locked with a padlock or other locking device to secure the carts' contents. These carts' doors and/or walls are made from steel expanded metal mesh, which has small openings that allow air to circulate through the cart and let users see items on the carts' shelves without opening the carts' doors.