Name : YangChenType of sports : Strength TrainingTraining Site : ARMS,BACK,Hand,Wrist,ChestOrigin : Mainland ChinaArm Exerciser Grade : 60kgFunction : ARMSModel Number : OUT210Feature1 : Gym apparatus,sports equipmentFeature2 : expanders,Hand StrengthenerFeature3 : bodybuilding pulley,home exercises machinesFeature4 : Arm wrestling,trainer handlesFeature5 : twister exercise,forearmFeature6 : exercises machineFeatureAdjustable ResistanceOur arm exerciser can be adjusted by rotating knob on left or right to increase or decrease the resistance from 22-440lbs in 2-20 levels. You don't need to buy another upper fitness equipment because our device can work great for all your needs. Please choose the resistance that suit for you to avoid muscle strain. It will accompany you throughout your fitness career.Hydraulic DesignOur hydraulic power twister features on safer micro rebound and refuse violent rebound. It can return softly to position without the violent spring back danger like the traditional spring exerciser. Patented hydraulic design will give your more effective, more stable and safer exercise experience. Say goodbye to the danger now.Fully Enclosed Hydraulic CylinderWhen the strength of spring power twister is reduced, the motion track becomes smaller which seriously affects the exercise effect. While our power twister uses a fully enclosed hydraulic cylinder which allows the device to provide with you a stable resistance strength. So even if you change the resistance, the opening angle of the arms remains unchanged, and the motion track is unchanged.Golden Ratio Triangle StructureTo let you exercise more safely with our power twister, we use the design of golden ratio triangle structure to keep the device in a stable state. What's more, The triangle structure with dual carbon steel and 10 reinforcement rivets, ensures the device more load-bearing capacity and durability. The device has passed 10000+ data test and 2650+ trial reports, confirmed that It is not easy to deform or break, and no leak from hydraulic cylinder during exercise.Easy to Use & StoreThe storage buckle at the handle's bottom make the Chest Expander device easier to store and convenient to carry. And ergonomic PU soft rubber handle will provide you with more comfortable grip. It is simpler and easier to use than spring exerciser. Use it for just 15 minute a day and three to four days a week, it will help build up your wrist, arm , chest, shoulder and back etc. upper body muscle at the same time whether you are beginner or expert.