Allows you to hold more weight on your lifts. Big lifts like bench press, deadlift, hang cleans, and curls of any kind are improved. More strength in your grip = more strength in your big lifts = more overall muscle.
Increased endurance. Your lifts no longer have to suffer in terms of quality because you can no longer grip something. Bars will stay glued to your hands and you can go deep into lifts until muscular failure, not grip failure.
HandGrip