In fact, most transfer carts are used in conjunction to a stationary conveyor system as a way of getting material to and from the conveyor. Topper Industrial is able to retrofit a cart design so that it is able to work with an existing conveyor system or line side equipment. Transfer Carts are offered as four wheel or six wheel carts and can be designed as push carts or tugger carts. Transfer Carts are often referred to as Industrial Carts with Roller Deck.