Detailed Size and Load Capacity: the steel plate aperture is 9/16 inch/ 14 mm, thickness is about 2/5 inch/ 10 mm, suitable for 1-5/8 inch wide and all 1-5/8 inch or taller strut channels; the single 4 wheel trolley assembly can hold up to 450 lbs. Heavy Duty: the trolley assembly is constructed from reinforced solid steel with galvanized properties, ensuring sturdiness and reliability, impact resistance, smooth and noiseless operation, resistant to breaking, deforming, fading, rust, and corrosion, designed for long-term use. Versatile to Use: the chain hoist trolley wheel is adaptable to various usage scenarios and is ideal for mounting on ceiling trolley systems or electric lifts; it can also be utilized in DIY projects based on your specific needs. What You Will Get: the package contains 4 pieces of beam trolley assemblies, capable of supporting a significant load, catering to your usage and replacement requirements, providing great convenience in daily life. Stable Performance: the 4 bearing trolley channel roller features welded bearings and pin shaft for safety and reliability, with a tight connection and stable performance ensuring smooth operation while minimizing noise.