Movers, dollies and platform trucks are tools for conducting conveyance work efficiently. Therefore, they can save the time and energy that manual labor would take up. Movers and platform trucks include collapsible type, dollies, container dollies, dollies with fences, etc. There are many products made in consideration of safety; some of them have casters with stoppers or the skid-proof function. The number of caster wheels are varied, such as 2-wheelers, 4-wheelers and 6-wheelers; the more number of wheels they have, the more stably they can travel. On the other hand, more number of wheels means that the travel resistance increases, and it is necessary to select the mover or dolly that suits the work site and use environment. Additionally, it is also important to take replacement casters (sold separately) into consideration, as there will be deterioration in wheel tires after use in a long term. There are also many dollies and container dollies that can be jointed one after another, making it possible to efficiently transfer large carts that are difficult to convey with human power.