Dumbbell finger curls train grip strength by letting the weight roll down to your fingertips and then curling it back into your palm. The finger flexors and forearm muscles do all the work through a longer range than standard wrist curls. Stronger fingers carry over directly to deadlifts, pull ups, and carrying anything heavy.
Log your dumbbell finger curls sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.