Magico Training Weights:

The Magic Training Weights (魔法のトレーニングウェイト), also known by the name of, "Dumbbells", They are magical training weights, made by Cid Kagenou, in a recreated way, so that he could go back to his daily training, when he reincarnated,increasing his innate strength, supremely, beyond human limits, in an evolutionary way, at the same time, allows him to stay in shape. Over time, he applied these tools and their variants to Shadow garden members, as a military training routine.