Neoprene coated with a cast iron core, adidas dumbbells help strengthen and tone broadening your exercise potential with 1-5 kg / 2-10 lb options to scale the difficulty. Featuring a unique hexagonal design, the dumbbells stay put once set down for added safety and ease of storage.Features:- Helps strengthen and tone- Neoprene coated with a cast iron core- Hexagonal design prevents rolling