Triceps
Chest, Shoulders, Forearms, Lats
Place board(s) of desired thickness on chest (held by spotter or tucked in shirt).
Lie on flat bench, set up for powerlifting bench press (arch, retracted scapulae).
Use close or medium grip.
Unrack bar.
Lower bar with control until it touches the board(s).
Keep elbows tucked.
Drive bar explosively back up to lockout.
Repeat. Focuses on triceps/lockout strength.