Specifications: Material:EVA Size:27*15*15cm Features: Water resistance: sealed foam structure, do not absorb water, prevent moisture Corrosion resistance: resistant to sea water, oil, acid, alkali and other chemicals, clothing, antibacterial, non-toxic tasteless non polluting Anti vibration: high resilience and tensile strength, high toughness Insulation: insulation, resistant to cold and heat Sound insulation: sound insulation effect is good Weight: density is 0.91-0.93, you can try to compare the buoyancy Package include: 2pcs EVA Dumbbell