HYDRODYNAMIC DESIGN:This swim paddles made of high quality polypropylene,comfortable to wear,blade and hole design,perfectly decrease the resistance in water, ensures your better performance Perfect Training Tool: This swimming hand paddles holes allow water to go through for a better control and workout,increase your shoulders and arms strength and improve your swimming power and skill Adjutable silicon strap: The adjustable silicon strap is for a secure fit, providing great stability for your palms when swimming and will not feel uncomfortable Ideal Gift for Swimming:Curved design for palm follow theory of nature mechanics,they are your best choice for practicability and comfort,well work for all four swim strokes freestyle,backstroke, breaststroke and butterfly Size: M size 19*17.6cm(L*W) for Adult.An excellent swimming accessory for beginners,experienced swimmers