AmazonBasics Neoprene Dumbbell Pairs and Sets with Stands, NuBells Dumbbells Set, Bowflex SelectTech 552, Quick-Lock Adjustable Dumbbell, CAP Barbell Adjustable Dumbbell Set, NordicTrack Speed Weights and the Omnie Adjustable Dumbbells are the best ones for a good abs’ workout. You can choose a per your level of comfort, as sometimes the simplest and most basic ones work well as abs dumbbells too.