1EASY TO LOCK: Built in iron metal attracting feature in the aluminum knob that help to lock and hold the weight stack and and maintain its durability and stability. 2DURABLE: The universal weight stack pins is made of iron and aluminum, which ensures that the weight stack pin is sturdy and durable. 3EASY TO USE: The weight stack pins are lightweight and easy to insert and remove, making them convenient for everyday use. You can easily adjust the pins to fit your training needs. 4LOSS PROOF DESIGN: The weight stack pins are equipped with a pull rope to ensure that they won't get lost. When you are done using the weight stack, attach the lanyard to the machine to prevent it from getting lost or slipping off accidentally. 5UNIVERSAL: This weight stack pin is a great fitness accessory to use at home or in the gym. It helps you to do more physical exercise, improve your body shape and strengthen your body. Item Type: Weight Stack Selector Pin Material: Iron, Aluminum Weight: Approx. 119g / 4.2oz Product Size: Approx. 8x125mm / 0.3x4.9in 1 x WeightStackSelectorPin