The target thrust reverser uses a pair of hydraulically-operated 'bucket' type doors to reverse the hot gas stream. For forward thrust, these doors form the propelling nozzle of the engine. In the original implementation of this system on the Boeing 707, and still common today, two reverser buckets were hinged so when deployed they block the rearward flow of the exhaust and redirect it with a forward component. This type of reverser is visible at the rear of the engine during deployment.