The most recent designs are of the single shaft type, as proponents believe that this type gives the dog(s) greater freedom, less possibility of injury, and a quicker and easier training regime. A single shaft dog sulky, made of stainless steel tube and fitted with independent suspension and disc brakes, weighs a little under 18 kg. The highest speed so far recorded in one of these sulkies is 64.8 kilometers per hour (Driver: James Walsh, Dog: Tom (Giant Schnauzer)-February 22, 2007, Australia).