Sit down on a decline bench with a pair of dumbbells resting on your thighs and with your legs securely hooked underneath the pads. The bench should be angled downward at roughly 30 degrees.
Carefully lay back on the bench and position the dumbbells at chest level, palms facing away and forearms/upper arms forming a 90 degree angle.
With your butt and shoulders firmly planted on the bench, press the weights up toward the ceiling in an arching motion until your arms are fully extended above you.
Lower the dumbbells back down until they are in line with your chest, and repeat.