Love this and highly recommend it. com y te explico como! maybe one with a screw closure rather than spring closure. Only thing is that the last several miles of my run my body heat caused the water to be warm. these are SOOOOO comfy! Small but heavy enough for a variation of exercises. ?? Great product and design. Recomendo a compra do conjunto,melhora demais a experiência de jogo. HOWEVER, it is DURABLE! If you drill a 5/32" pilot hole and use the CORRECTsize phillips screwdriver (#3) the hardware is fine.