Pec Deck Butterfly Machine

A pec deck is a machine designed to increase strength and muscle mass in the chest. It's so effective that the American Council on Exercise ranked it as one of the best exercises for building chest muscles.A machine fly, alternatively called a seated lever fly or "Pec Deck" 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.