Our weight plates are filled with iron sand and wrapped with high-grade PE materials. The thickened foam connecting rod conforms to the ergonomic design, reduces the pressure on the shoulder, avoids sports injuries.The connecting bar is made of 5mm thick steel tube + 20mm thick high quality foam, soft, non-slip, sweat-absorbent, curved design ergonomic, close to the neck, reduce the pressure on the shoulders, so that you are more comfortable during the workout.The set contains four safety nuts.