lowered to the ground in a substantially horizontally fashion and the motorcycle has only to be rolled or ridden over the lip of the platform and secured to it, whereupon the entire platform and load are raised and secured for towing. Such designs only require the machine be raised by the thickness of the platform, which is typically less than 10 cm (4 in). Numerous mechanical designs have been devised by trailer fabricators to achieve this goal. Trailers pulled behind motorcycles Trailers towed behind motorcycles are distinguished by their relatively small size, especially narrow wheelbase. They are also often styled to match the look of the motorcycle they are intended to be towed behind. This styling can include the overall shape, fender shape, lights, chrome, etc. Types Cargo trailers Cargo trailers provide extra storage space on for bikers whose motorcycles have little storage. The most popular models are made of fiberglass or aluminum and ride on two wheels. Open or utility trailer Motorcycle utility trailers are uncovered, single-axle, flatbed trailers. These trailers are designed to be towed by a motorcycle, so they are much smaller than standard open trailers which must be towed by a four-wheel vehicle. Dog trailer Motorcycle dog trailers are designed to transport the animals in safety and comfort. They are fully enclosed, well ventilated and have suspension. Motorcycle camping trailers Two types of trailers prevail within the motorcycle camping trailers category: clamshell and platform camper trailers. Fabric material is attached to the top and bottom halves of the clamshell trailer. The tent is created when the trailer is opened. Once a platform camping trailer is opened, however, the tent is pitched on it. These platform style camping trailers are larger than clamshell camping trailers and can fit full-sized to king-sized air mattresses. Most often, clamshells can only accommodate a single occupant. The Pav 40/41/100 The Pav trailers were manufactured in the Czech Republic, originally by "AVIA n.p". and later by "KOVOZAVODY SEMILY" by Jawa Moto. Earliest examples were made in the mid- to late-1950s, which pre-date the PAV 40. The PAV 40 debuted in approximately 1958 or 1959. The PAV 41 eventually replaced the PAV 40 and was produced into the 1970s. Pav trailers feature a single wheel and are rated to . They were made to be attached to Jawa motorcycles, although they make excellent accessories for Vespa, Lambretta, Cezeta, Heinkel, Fuji, Zundapp, Cushman, or