These handy magnetic parts trays are ideal when working on your project no matter whether under the hood or under the car. Use it vertically or horizontally because it is darn handy. It helps keep small parts from running away or being deposited where you wish they hadn't gone. The tray portion is made from stainless steel to prevent corrosion and the heavy magnets are protected with a durable rubber coated boot. As with all magnets, they will not connect to fiberglass or carbon fiber hoods or body panels.