A machine fly, alternatively called a seated lever fly or “Pec Dec” fly is a strength training exercise based on the free weight chest fly. As with the chest fly, the hand and arm move through an arc while the elbow is kept at a constant angle.
While primarily working the pectoralis major muscles, using a pec fly machine requires some support from the pectoralis minor muscles in the chest, the deltoid muscles in the shoulders, and the serratus muscles in the rib cage.