1- Place the weight in your lap and put your hands on the edge of a bench with feet on the floor and elbows slightly bent and close to the body.
2- Inhale and start dipping down by bending your elbows until they form 90 degrees angle with shoulder level.
3- Slowly return up to the starting position by forcing on triceps.
4- Exhale at the end of the movement, and repeat.
Tips and Advises:
1- keep your back straight during the exercise if you want to focus on tri.
2- Lean forward if you want in involve the chest.
3- Wider the elbows to work chest more, whereas keep the elbows close to your body to focus on tri.
Variation:
1- Seated Dips
2- Bench Dips
3- Weighted Bench Dips