Powerful Stainless Steel Pulley BlockEach U Type Single Wheel Pulley Block has 4 mounting holes and the diameter of each hole is 7mm, which fits for 3-12 mm width flat belt. It be mounted on various walls, wood and metal. (Equipped with 4 pcs 6*40mm self-tapping screws and 4 pcs 10*60mm yellow expansion pipes.) Superior Groove WheelThe Single Wheel Lifting Rope Pulley Block is made of stainless steel, which is durable and easy to clean. The thickened steel plate enhances the bearing capacity of the Rope Pulley, which carry up to 800 pounds. Super Mute Duplex Bearing DesignThe Silent Duplex Bearing greatly reduce the friction of the cable pulley and make the cable pulley rotate smoothly and stably. You hardly hear the sound when it works. Wide ApplicationThe Wall Mount Pulley Block is widely used for home fitness, wire rope traction, DIY attachment for home gym pulley system, inverted track, lifting blocks, ladder lift, gym equipment, rolling gate sliding gate and other outdoor works. Easy InstallationThe pulley is designed for easy installation. You just need to mark the hole location, drill 4 holes with a 10 mm drill bit in the wall and insert the yellow expansion pipes in the holes, finally, fix the pulley with the self-tapping screws.