FEIERDUN Water Exercise and Aerobics Foam Pool Dumbbells Weights - Maximum Resistance Pair - 14 Page Instructional Handbook Included Exervo premium AquaComfort EVA foam for durability. Maximum means high resistance UV & bacteria resistant plus water beads right off EVA foam for super fast drying 5 inch thick x 6 inch round foam on each end of dumbbell. Suited for conditioned & experiences exercisers This is a higher resistance dumbbell. Also available in Light, Medium, Heavy & Supermax resistances Free 14 page instructional starter guide demonstrating basic water dumbbell exercises