It's a trotter.
sulky
Standardbreds are used for harness racing.
The gaits used by harness racing horses is pacer and trotter
Arabians are not used for harness racing in the US, only Standardbred horses are used for harness racing in the US.
A sulky is always used in harness racing. It is the cart where the jockey sits.
A breed of horse heavier than the Thoroughbred, but similar in type. Standardbreds have a calm temperament and are used in harness racing.
Horse Racing, Harness Racing, Polo, Dressage, Horse jumping, Cross Country ( 3 day eventing). Showing horses in hand, Rodeo, Long Distance ( endurance ) riding.
Jockeys ride on the back of thoroughbred horses; standard bred horses used in harness racing have drivers.
Horse shoes are compulsory in horse racing. If a horse loses a shoe, it is pulled out of the race.
Harness racers may be called Harness horses as a general term. They have two gaits, the pace and the trot. Trotters trot, and Pacer's pace. They could also be called by their individual breeds. In the USA only the Standardbred is used for racing. In other countries they have other breeds such as, but not limited to, Orlov Trotters, Russian Trotters, French Trotters and a few others.
It is called the crupper.
a harness and a saddle
Aluminum horse shoes are mostly used for Thoroughbred Horse racing.